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Running Windows or macOS on the G.R.I.D. Lab iMac computers

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The iMac computers in the G.R.I.D. Lab can run either the macOS operating system or the Windows operating system, thus giving them access to a wide variety of software programs.

This page describes how to run the operating system of your choice on these iMac computers. You can only run one operating system at a time. Switching to the other operating system requires restarting the computer. This page only shows the startup procedure. See the lab FAQ if you are having trouble getting logged in once the operating system has started.

This page first shows how to start the computer in the operating system you want, if it is currently turned off. Then it gives directions to switch from running macOS to Windows. Finally, it gives directions to switch from running Windows to macOS.

Starting the right operating system when the computer is off

If the iMac you want to use is completely turned off, you can start directly into the operating system of your choice.

Press the power button, which is located near the left bottom of the screen, on the back side. 

Use the standard Mac method of choosing a boot disk by holding down the Option key while starting or restarting.

Mac option boot

Use the arrow keys or mouse to select either "Macintosh HD" for macOS or "Windows"  and then click on the up arrow underneath your selection to start that operating system.

Switch from macOS to Windows

If the iMac you want to use is running macOS, you must restart to switch to Windows. As the computer restarts, you need to hold down the Option key again during the restart to give you a choice between Windows and macOS.

Here are two sets of instructions for initiating a restart from macOS. The first case, immediately below, describes what to do if you (or someone else) are logged into macOS. The second case, which follows after, shows how to restart if macOS  is running, but no one is logged in.

Restarting if logged into macOS

Your iMac is logged into macOS if it shows the macOS desktop, like this (background image and open application windows may vary)'

Mac OSX Desktop

 

Be sure to save your work and close all open applications first. Then click on the Apple menu in the upper left corner, and then click on the item labeled Restart..., as shown in this screenshot.

Max OSX Restart menu

 

A dialog box will appear to confirm that you really want to restart, as shown in this screenshot:

Mac OSX logoff confimation menu

 

Click on the Restart button to proceed with the restart. Hold down the Option key during restart and you will be given a menu to select Windows using the arrow keys, otherwise it will just restart back into macOS.

Restarting if macOS is running, but not logged-in

If macOS is running, but no one is logged in, moving the mouse or pressing a key on the keyboard should bring it out of sleep mode and show these elements on the screen:

Mac OSX Login

 

Simply click on the Restart button to proceed with the restart. While the computer is restarting, be sure to hold down the Option key to bring up the boot menu.  You then select “Windows”.

Switch from Windows to macOS

If the iMac you want to use is running Windows, you must restart to switch to macOS.

Here are two sets of instructions for initiating a restart from Windows. The first case, immediately below, describes what to do if you (or someone else) are logged into Windows. The second case shows how to restart when Windows is running, but no one is logged in.

Restarting if logged into Windows

Your iMac is logged into Windows if it shows the Windows desktop, like this (background photo and open application windows may vary):

Windows 10 desktop

 

You should save all the work you are doing and close all open applications first. Then click on the Start button (Windows logo) in the lower-left corner to bring up a window with a list of programs and things to do. After this window opens, If you click on the button in the lower-left corner, it will bring up a menu of power-related options, like this:

Windows 10 right click menu

 

Click on the Restart option in this shutdown menu. While the computer is restarting, be sure to hold down the Option key to bring up the boot menu.  You then select “Macintosh HD”.  See the startup directions above.

Restarting if Windows is running, but not logged-in

If Windows is running, but no one is logged in, moving the mouse or pressing a key on the keyboard should bring it out of sleep mode and show a welcome window like this (the background photo and time will vary):

Windows 10 Welcome screen

 

As the screen says, press the Control, Alt, and Delete keys at the same time to begin. A Stanford policy window will appear, as shown in this screen picture:

Windows 10 Stanford policy

 

Click on the OK button or hit the Enter key to acknowledge that you agree with this policy. That will take you to the login window, as shown in this screen picture:

Windows 10 login screen

 

Notice the icons in the lower right corner of the screen. If you click on the rightmost button, it will bring up a menu of power related actions. Select the "Restart" action, as shown here:

Windows 10 shutdown icon

 

While the computer is restarting, be sure to hold down the Option key to bring up the boot menu.  You then select “Macintosh HD”.