Restart Usb Service Mac


The new MacKeeper app delivers a secure and private internet experience while helping your Mac run like new. It has been designed to work with PassMark BurnInTest but will also work with 3rd party application. Restart the computer. net rpc service list -I 192. Navigate back to the General PC settings and boot into Advanced Startup. USB bandwidth contention is the primary correctable cause of poor performance and can often be resolved by plugging the Leap Motion controller into a different USB port, plugging the controller directly into the computer rather than using USB hubs or extender cables, or removing other USB devices. For those working from Linux this task can easily be accomplished via the Linux Flash Drive Restoration tutorial that follows. Set up your HP printer for a USB cable connection to a Mac computer. About At Your Service Xerox products big and small have many features, options and services. But it's still a tough case for ordinary users to fix when their Mac computers fail to boot after macOS High Sierra update or installation. Once you are done installing Windows 10 on your Mac, you would want to know how to alternatively boot into the two operating systems. Follow these quick steps:. For macOS, download the latest version of the iLok License Manager to obtain the uninstaller file. After identifying the service you want to stop, start, or restart, you can issue the following command to stop the service:. ABOUT TRIPP LITE. Apple has confirmed the USB bug that causes a kernel panic on some systems a few minutes after startup. Windows doesn't always allow you to safely remove a flash drive or external hard drive. This wikiHow teaches you how to safely reboot your Windows or macOS computer. For a long time, Microsoft didn’t sell Windows install media in the form of bootable USB flash drives. 115 -U Windows%myPassword. Here you can pick which drive you want to boot from. exe on your desktop. The one caveat is that all the start, stop, and restart options do is pass this argument to the various scripts. About this Product. For users, we offer a consistent manageable platform that suits a wide variety of deployments. If you will need to use the Internet, select 5 (F5) for Safe Mode with Networking. This wikiHow teaches you how to shut down and restart a Mac computer that has become unresponsive. Purchasing a USB Drive for Your OS X Recovery Disk. Mac Pro has extremely high-performance I/O, and lots of it. Restart-Computer -ComputerName "Server01"-Wait - For PowerShell -Timeout 6 00-Delay 2 The Delay argument determines how often, in seconds, Windows PowerShell queries the service that is specified by the For parameter to determine whether it is available after the computer is restarted. Restart the Windows File Sharing Service to fix weird problems September 23rd, 2011 Every once in a while I get this annoying problem where I can't a access my windows shares from other computers on the network, and the only way to get it it to work again is to restart windows. It brings the scale, agility and elasticity of the cloud on-premises with efficient N+1 clustering based on Check Point's HyperSync technology, thus maximizing the capabilities of your existing Security Gateways. The same methods can be used to restart a service in Windows 10. Double-click the DisplayLink Installer 75598. bash_profile sourced etc). A reboot is a simple way of solving common hardware problems. Use the arrow keys on your keyboard to select the Windows drive. Just restart your PC and see if it is working. It will help you in your journey of discovery with Linux. Water lodged in the USB port may cause the phone to falsely detect an inserted USB cable until the water is removed. You wake up or restart your Mac, and nothing is connected. Sending stop or restart to this script has no effect. However, if you've decided to use a third-party program or used Target Disk mode to erase your Mac, you should follow these additional steps to ensure that your Touch Bar data is also erased. How to boot from macOS Mojave USB Install Drive. This will cause the Mac's Startup Manager to display a list of drives you can start from. How do I restart USB devices? One of the properties is called 'Service'. As unplugging and replugging a USB cable is scary to some of my teachers - is there a command line thing I can run to restart either a specific or all usb ports. In that mode Jenkins don't start any build. Click on the Restart button to reboot your computer. Insert the USB boot media into an open USB slot. 10 Yosemite in the Mac App Store for everyone to download and install for free on October 16th, 2014, but downloading a 5+ GB file for each of your computers will take some serious time. You have the option to schedule the Windows client computers to restart during a time that is convenient for users. Select Print & Fax or Print & Scan, select your product, and select Options & Supplies. It has been designed to work with PassMark BurnInTest but will also work with 3rd party application. Using the Start menu. For a version of Symantec Endpoint Protection earlier than 14, you uninstall the Symantec Endpoint Protection client for Mac with the Symantec Uninstaller. USB RS232 - FTDI designs and supplies USB semiconductor devices with Legacy support including royalty-free drivers. When you need to start, stop or restart the Apache (httpd) service on Mac OS X. Restart-Computer -ComputerName "Server01"-Wait - For PowerShell -Timeout 6 00-Delay 2 The Delay argument determines how often, in seconds, Windows PowerShell queries the service that is specified by the For parameter to determine whether it is available after the computer is restarted. And with every MPX Module you add you get more capability. It can be used to start, stop, and restart the Apache web server from command line. USB problem. NVRAM, or non-volatile random-access memory, is a part of the Mac that stores certain settings that can impact hardware performance. Insert the USB boot media into an open USB slot. More iXpand USB 3. Now connect your iPad or iPhone to your computer using either USB to 30 pin, lightning cable, USB-C and/or USB-C to USB-C (the same one you use for charging) and voilà! When duet detects the iPad or iPhone it will change the message from Connect to Mac/PC to Launching Duet right before your new desktop is displayed on the computer. Roxio Easy VHS to DVD for Mac Includes everything you need to easily transfer video from VHS, Hi8, V8 or analog camcorders to DVD. Restart the print spooler service whenever you cannot remove a job from the print queue. Mac restart is able to use 'Soft Restart' and 'Hard Restart' to restart your Mac. • Mac OS X 10. Use the Guide to find shows. My question was for one-time "restart" and temporary "stop" actions that should not have a permanent effect. This portable turntable is tough and durable, so you can take it with you anywhere. When your download is complete, run the Dropbox installer. Holding that key gives you access to OS X. How to Shutdown, Restart, Sleep or Log Out on Mac with Keyboard shortcuts only - iOS Hacker. Upon completion, the Neato robot will play the start-up chime and then show the main screen on its LCD. This application is provided as-is. The SKS keyserver network has been a victim of certificate poisoning attack lately. This tutorial describes how to install a Linux print server with CUPS. Connect up to 12 4K displays or up to six Pro Display XDRs from Apple and see your work with over 120 million pixels. To get the most supported features from a USB connected printer, install the full feature HP driver. If your Mac fails to shut down, press and hold the power button until the Mac shuts down, which usually takes 10 seconds or so. On your Mac OS X learn how to block or Disable USB port on Mac, MacBook, Pro for temporary or permanently. Method 2: Use a Bootable Disk Drive Utility. I've just started to use Jenkins as part of a continuous integration setup that I'm building. All gets back to normal after restart. This means that irrespective of the OS of the backed up computer, the backup can be accessed from any PC, Mac or Linux system. Restart your computer. There are separate commands to restart the network services and to restart a particular network interface. Here’s how to reset Apple TV and other troubleshooting techniques. From there, you'll have to search for a more long-term solution. Get technical support for Kaspersky Lab products for home & business. Double-click Disk Utility. I have set the service "Microsoft Office Click-to-Run Service" to Disabled because I can't stand using OneDrive and OneDrive (Office. One final restart and then your USB serial devices should all be loading properly! you agree to our. Introducing Kies for your Mac computer. It also covers the installation and configuration of printer drivers on the print server as well as the printer setup on a Windows 2000 client. Apple has confirmed the USB bug that causes a kernel panic on some systems a few minutes after startup. How to boot from macOS Mojave USB Install Drive. The CentOS Project. Samsung Galaxy s7 connected to PC but not detecting any files. If you haven't a Windows installation media, then you can create one directly from Microsoft. Why does my network connection drop every so often? There are many possible reasons so I’ll focus a common one: confused network auto-speed detection. Software Downloads. To restart ssh/sshd service in Mac OS X, you can simply run the following two commands together: sudo launchctl stop com. Restart your Mac. To use any of these key combinations, press and hold the keys immediately after pressing the power button to turn on your Mac , or immediately after your Mac begins to restart. Plug the external drive only to the USB port. A motherboard that is capable of booting from a USB drive (check your motherboard manual if not sure) As long as you have all three points above met, then you are ready to start. Creating USB install media. This is an alternative key combination to force restart a Mac. Click Restart Applet as Windows System Service (or Mac OS X daemon). Installing macOS on a USB Drive. If your Mac mini needs service, consult the service and support information that came with your computer for instructions about how to contact an Apple Authorized Service Provider or Apple for service. Restart your Mac. Newest Aug, 2 2019 RDP-UDP data tunneling is not working Jul, 31 2019 Accepted SSL Ciphers. Here’s how to reset Apple TV and other troubleshooting techniques. Even though TransMac is a paid software, the 15-day trial copy is good enough to prepare the bootable USB of Mac on your PC. This works for USB drives including the NinjaStik For 2018 / 2019 Macs with the Secure Boot T2 Chip, see the 2018 Macbook Pro Boot from USB instructions. All USB Ports have suddenly stopped working Mini Spy. Our award-winning lineup includes memory cards, USB flash drives, readers, SSDs and storage drives for retail and OEM customers. Note: Do not set the "Reapply" behavior when taking this action or you may cause the BES Client to constantly restart itself. How to Restart a Mac Computer If your Mac desktop or Mac laptop is acting sluggish or programs are failing to run, you need to know how to restart your Mac computer. Download Legacy Version. The software lets you share USB over IP on Windows, Mac, and Linux machines. Upon completion, the Neato robot will play the start-up chime and then show the main screen on its LCD. Once the Boot Camp drivers have completed download, click Quit. Then restart the Adobe application. On most phones, press the Power button for about 30 seconds, until your device restarts. Select Utility and select Open Printer Utility. It allows you to add an additional Gigabit Ethernet (JCE131, JCH471) and 3 USB 3. It even keeps a log for administrator tracking and troubleshooting. These drivers are designed for use with those GPS units that support USB transfer of data to/from the PC - not to include the iQue. Windows 10 USB ports reset/drop/restart - causing wifi drops internet connection I searching for a solution as why my all of my USB ports will just randomly lose connection. If your ISP claims your router is the cause of an outage, you may be able to get around the problem by cloning your computer's MAC address. For you, LiLi creates portable, bootable and virtualized USB stick running Linux. Here’s what that means, and how to do it. External hard drives only recognized after restart Feb 19, 2012 Since upgrading to latest version of Lion, I find that my two external hard drives are only recognized after a restart, not from a cold boot. nmcli is a tool that allows NetworkManager management from command line. You can start/stop/restart MySQL Server via the command line. NVRAM, or non-volatile random-access memory, is a part of the Mac that stores certain settings that can impact hardware performance. as i tried to fix my mac so it will run the normal way, after i did the cmd-s i got a message that i have incorrect number of thread recods. If it mounts, eject it using Finder and then physically unplug the usb cable from the drive. I have had two over the last decade or so, and they are super reliable and very affordable. 0 hard drives, due to differences in access. When you get to the Windows 8 logon screen, log on to the computer and perform any. In Docker 1. External hard drives only recognized after restart Feb 19, 2012 Since upgrading to latest version of Lion, I find that my two external hard drives are only recognized after a restart, not from a cold boot. If you are using a high-powered USB device please attach the power adapter that. How to fix the "PC Ran Into a Problem and Needs To Restart" problem if you CANNOT start Windows Normally or in Safe Mode. (Mac) Fail to launch PdaNet background service 2, err=61 (or 60) Try to uninstall PdaNet on Mac first (run ~/PdaNetUninstall. Restart-Computer -ComputerName "Server01"-Wait - For PowerShell -Timeout 6 00-Delay 2 The Delay argument determines how often, in seconds, Windows PowerShell queries the service that is specified by the For parameter to determine whether it is available after the computer is restarted. Samsung Galaxy S7 USB Drivers for Mac. Why is this not Mac related? It's about USB ports on his Mac, and how to restart the USB system on the Mac, not on Arduino. Docker for Mac has a neat little 'restart' button in the dropdown from the whale icon in the menu bar. In Geostationary Orbit. To get the most supported features from a USB connected printer, install the full feature HP driver. Troubleshooting. How to write a USB stick with Windows. USB power bricks or chargers are able to supply power through a laptop’s USB ports. The new MOXF music production synthesizer workstation series combines a MOTIF XF sound engine and Flash memory expandability, a MIDI keyboard controller with extensive DAW and VST control, USB Audio/MIDI interfacing, onboard sequencing, and an extensive DAW / VST software bundle. is a consumer technology company based in Cupertino, California. If your Mac fails to shut down, press and hold the power button until the Mac shuts down, which usually takes 10 seconds or so. Mac startup key combinations Learn about the Mac features and tools that you can access by holding down one or more keys during startup. USB RS232 - FTDI designs and supplies USB semiconductor devices with Legacy support including royalty-free drivers. MagicJack is an external hardware that helps users to make phone calls from computers by utilising USB connectivity. Just restart your PC and see if it is working. As unplugging and replugging a USB cable is scary to some of my teachers - is there a command line thing I can run to restart either a specific or all usb ports. You can use LaCie Setup Assistant to format your LaCie hard drive when it is first connected to a computer (Mac or Windows). Snag a pair of USB-C to USB-A cables for just $5. Then turn on your MacBook Pro or iMac. flash drive repair free download - USB Flash Drive Format Tool, USB Flash Drive Tester, Format USB Or Flash Drive Software, and many more programs. How to Restart a Mac. Drivers Updates – manual Driver fixes. There is a restart button on the toolbar in the Services snap-in. Restart your computer: Restart your Mac or PC computer and try connecting again. Whether you need to run Windows programs that don't have Mac versions, or you're making the switch from PC to Mac and need to transfer your data, Parallels Desktop has you covered. Lenovo Inc. Wait 30 seconds or 5 minutes then plug it back in. The ultimate fix for many technical glitches on a PC. Then insert the DSC Usb Tokens and install the concerned software related to the DSC issuing Authority. To restart ssh/sshd service in Mac OS X, you can simply run the following two commands together: sudo launchctl stop com. Then enable when you want by reset USB port. https://my. Open Task Manager and go to the Services tab. Holding that key gives you access to OS X. Look for the power button on the back of a desktop Mac, and at the top right of the keyboard on most laptop Macs. This tool is the Microsoft Sysinternals PsExec tool. An example is AppServices, which controls coreservicesd. By John Martellaro. 5GHz (MD387LL/A), 16GB Memory, 1TB SSHD (Solid State Hybrid) Drive, ThunderBolt (Renewed) 3. Canon PIXMA MG3600 is an all-in-one Wireless Inkjet printer that delivers simplicity and convenience for your print job. Select Audio I/O tab at the top left. I tried Activity Monitor, but it only kills processes, it does not start them. 0 iXpand USB 3. The issue is often caused by insufficient power supply to the USB hub of the computer. A majority of end users might not be familiar with the purpose of restarting the OS X Dock. The first step in our USB port troubleshooting is the easiest one: a simple reset of the Mac. Check the USB device to see whether it is working. Let Xerox Customer Support help you understand and use the features, options and services available for your production, office or small business products and laugh a little along the way. Windows 10 USB ports reset/drop/restart - causing wifi drops internet connection I searching for a solution as why my all of my USB ports will just randomly lose connection. Its icon indicates the current status of your Router and also allows you to access your Router’s settings to make changes. Create and manage USB drive images. An example is AppServices, which controls coreservicesd. How to write a USB stick with Windows. We’ll also cover how to factory reset and restore your Apple TV in case all else fails or you decide to sell your Apple TV at some point. I tried Activity Monitor, but it only kills processes, it does not start them. Restoring your USB key to its original state using Windows/Mac OS: – Manual Method via Diskpart – Windows:. Today I was at the office with my tablet (XOOM, Jelly Bean, non-rooted), my Mac was at home (2008 MacBook Pro running the latest point release of Lion) I used the latest version of Splashtop on my XOOM to connect to the MacBook Pro at home (running the latest point release of the streamer). Why you shouldn't ditch that broken USB memory stick just yet Another way you could restart your USB stick is by using Windows Disk Management, which again wipes the content. Stopping & Starting Windows Services from the Mac Using net rpc from the Command Line. Boot Camp lets you install Windows on a Mac computer in its own partition, so you can use either Windows or Mac OS X on your Mac computer. Connect up to 12 4K displays or up to six Pro Display XDRs from Apple and see your work with over 120 million pixels. Refer the below link to download for your Mac. List of Freeware to Create Bootable USB Drive to Install Windows and Linux - Many times we need to install fresh Windows or a Linux distro in a computer system but we don't have access to a working CD/DVD drive. Download foobar2000 for Mac. When the computer powers up again, look for a BIOS setup message, which often looks like “Press [KEY] to run Setup” where [KEY] might be Delete, ESC, or one of the F1–F12 keys. To format a drive on a Mac, you'll need the built-in Disk Utility application. Service is Started on Restart but Service Set to Disabled in General Support Service is Started on Restart but Service Set to Disabled I am new to WIN10, and I find this behavior puzzling. If your Mac mini needs service, consult the service and support information that came with your computer for instructions about how to contact an Apple Authorized Service Provider or Apple for service. The usbprint service is using the usbprint. 2 for macOS Mojave. The installed version of iTunes may also be too old. iXpand Flash Drive USB 3. This is temporary, but it will prevent you from holding the power button to force a restart. 115 -U Windows%myPassword. Use SkipMode ®. Sometimes a user may face connectivity issues while using MagicJack. After identifying the service you want to stop, start, or restart, you can issue the following command to stop the service:. For over 15 years, Powerbook Medic has been providing parts, repair, and service for a variety of gadgets. In your Downloads folder, open the Remove2011-master folder. Its icon indicates the current status of your Router and also allows you to access your Router’s settings to make changes. Every project on GitHub comes with a version-controlled wiki to give your documentation the high level of care it deserves. Step 4: Now follow the prompts and install the macOS 10. Whether you need to run Windows programs that don't have Mac versions, or you're making the switch from PC to Mac and need to transfer your data, Parallels Desktop has you covered. In this tutorial we will learn how to make Ubuntu disable a specific network adapter automatically at system startup for both wired and wireless connections. it did few checks. To use any of these key combinations, press and hold the keys immediately after pressing the power button to turn on your Mac , or immediately after your Mac begins to restart. Restart the browser If you still cannot access your Account page and have a billing-related question, click here to fill out a personal assistance ticket. 0 DVI Display Adapter with VGA and HDMI Adapters service@j5create. The Restart Page. Launch Android Backup Restore on your computer and select Data "Backup & Restore" option. Apple has confirmed the USB bug that causes a kernel panic on some systems a few minutes after startup. This wikiHow teaches you how to shut down and restart a Mac computer that has become unresponsive. 5 ways to restart a Surface Pro 3 or Pro 4 tablet. That’s not entirely accurate. Exit all the open applications. To restart a service, you can use the launchctl kickstart command, together with the -k option. 4+) start Print and Fax from System Preferences. I think I may know what is causing the problem now, I have been using a USB hub and the last time the mouse stopped working it was a result of a conflicting device also using the hub. The wifi dropdown beachballs and on the Network System Prefs panel the list on the side is empty. Then click Shut Down. Press the button again to restart it. How to get into Recovery Mode on iPhone 7. The website of Gentoo, a flexible Linux or BSD distribution. If the script doesn't respond to that argument, nothing happens. On your Mac OS X learn how to block or Disable USB port on Mac, MacBook, Pro for temporary or permanently. C: Restart and boot from an optical or USB drive. Dust off any old USB keyboard and get your Bluetooth back in action. Parallels Knowledge Base. UEFI (Unified Extensible Firmware Interface) is a standard firmware interface for new PCs pre-installed with Windows 8/10, which is designed to replace BIOS (basic input/output system). Instant USB Audio The Cable Matters (2-Pack) USB to Stereo Audio Adapter for Windows and Mac provides an instant upgrade to the audio jack on your computer or laptop. On J series Tizen TVs, you can try turning off Menu -> Smart Hub -> App Auto Update to avoid losing the application on every TV restart. Create a Bootable USB for windows 10 and install it on your Mac by the steps mentioned above. The Restart-NetAdapter cmdlet restarts a network adapter by disabling and then re-enabling the network adapter. make sure the format is Mac OS Extended (Journaled) and click 'Apply'. conf file to detect added or removed non-USB readers (serial or PCMCIA). Thunderbolt 3 docks and adapters will only work with Thunderbolt 3 USB-C computers and ports. 115 -U Windows%myPassword. tgz archive file to the Mac client computer. Produplicator provides HDD hard drive, SSD solid state drive, USB drive, SD microSD or CF card, DVD CD Blu-ray Disc duplicators. Try restarting without holding down the C key. H ow do I restart Apache web server under Mac OS X operating systems? The apachectl command act as Apache HTTP Server control interface. Make sure the userwidget directory is located in the root of your USB drive. Occasionally, a Mac can become stubbornly uncooperative and refuse to accept inputs. To restart the McAfee Agent services on a Mac: In the Finder, click Go , Utilities. USB power bricks or chargers are able to supply power through a laptop’s USB ports. 0 (All Thunderbolt Apollo Models) More Universal Audio YouTube Channels. usbhost: Shows information about USB devices attached to the host, including information useful for constructing USB filters and whether they are currently in use by the host. Mac OS X El Capitan 10. If your problem continues after restarting the Apple Mobile Device Service, you may need to remove and reinstall AMDS and iTunes. Mac restart is able to use 'Soft Restart' and 'Hard Restart' to restart your Mac. Then type ``/sbin/shutdown -r now''. This article describes how to delegate IPv6 prefix from delegating router (Prefix Delegation Server) to a requesting router (Prefix Delegation Client) and use those prefixes to. Step-by-Step IPP based Print Server using CUPS. is on the list), select the process and click Quit Process. This tool creates a bootable USB drive from your Mac App Store purchased copy of macOS. If it doesn’t, restart the download. For Mac, users can easily transfer data using a special tool called Android File Transfer. If you select "USB" and "Mac" on this download page, it gives a series of command line instructions to make a USB key which the MacBook will boot into Ubuntu from. USB Network Gate (former USB over Ethernet Connector) is the software that easily connects one or more remote USB devices to your computer over Network (Internet/LAN/WAN) as if the device was plugged into your own machine. Backblaze B2 Cloud Storage is our latest product offering, which offers the lowest priced enterprise cloud storage service on the market. To install Windows, restart the installation. We carry all kinds of Apple Macintosh parts for all Mac Models. how to instal windows 10 on mac. 7 from the command line:. How to Shutdown, Restart, Sleep or Log Out on Mac with Keyboard shortcuts only - iOS Hacker. Kies support for your Mac is also available to help you manage your data transfers. scan and Print from virtually anywhere around the Office and your home with wireless support. Manage your GPG Keychain with a few simple clicks and experience the full power of GPG easier than ever before. The second method to install OS X is to restart the Mac If you have a newer Mac and a USB drive. 1 and restart your Mac machine. Follow the steps below and restart your computer when finished. It has been designed to work with PassMark BurnInTest but will also work with 3rd party application. Macs, iPods, and thousands of accessories, new, used, and refurbished. There may come a time when your Windows 10-powered machine will just not recognise a USB device. On most phones, press the Power button for about 30 seconds, until your device restarts. 6 6) Motorola USB Driver: 1. All can be done with 1 click. • Mac OS X 10. See the screenshot below. Your issues matter to us. If you're having trouble using USB devices with your Mac, resetting the USB ports makes them operational again. It's not just my USB wifi device, but my USB Mouse, USB Webcam, and USB keyboard, they stops working. Insert the USB boot media into an open USB slot. There are times when it's necessary to restart the Mac's Finder. non-Tizen TVs (E/ES/F/H/HU/J4/J52):. To restart ssh/sshd service in Mac OS X, you can simply run the following two commands together: sudo launchctl stop com. ifconfig is empty, not even a localhost loopback. Based on your feedback, the feature to restore applications that have registered for application restart after you. After that plug everything back in power cord, USB audio jack everything Then run disk utility turn off and turn on your Mac and hold the command and R keys together. Polar V800 needs to be in the time view when you start syncing. NetworkManager status. Plug the external drive only to the USB port. The Restart Page. But installing Windows Vista from a high speed USB flash drive perhaps is the easiest & fastest way to complete a Windows Vista install which nowadays every computer or laptop have a USB drive. Restart your Mac and plug the USB cable back into your Mac and see if it shows up as Read/Write. The website of Gentoo, a flexible Linux or BSD distribution. Its icon indicates the current status of your Router and also allows you to access your Router’s settings to make changes. Fix 6: Restart the PC or Mac and iPhone XS Max, iPhone XS, XR, X, iPhone 8 Plus. ) Perhaps it's. I rewrote it in PowerShell and was pretty happy with the results so I thought I would share them. Press ‘Default’ and check the list of printers connected to your Mac. They quickly understood my needs and provided excellent solutions and service at a very reasonable price. Restart your device: try connecting again. Hi All, When I was using Window XP I could restart in Mac OS by clicking on the Bootcamp icon at the bottom right of the screen. Your issues matter to us. Exit all the open applications. Now restart you Mac and hold these keys down as the Mac starts-up.