How to shut down the computer without the update on Windows 7?

You can press Ctrl + Alt + Del and choose shutdown from the bottom right menu. It will not install updates if shutdown from this interface.

There is a Registry Hack provided by The How-To Geek on how to disable this here:

Stop Windows Update from Hijacking the Sleep/Shutdown Button

Add a 32-bit DWORD value called NoAUAsDefaultShutdownOption to HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\WindowsUpdate\AU with a value of 1. No reboot should be necessary.

You can apply it manually or download the registry file which enables and disables this feature. I deploy it to all Windows 7 machines I own and it works beautifully.

Easy way, press Alt + F4 on the desktop then select "Power Off" (or "shutdown", something similar...)

I tested it by myselft and confirmed this works:

1. Go to Start
2. Run
3. gpedit.msc
4. User Configuration
5. Administrative Templates
6. Windows Components
7. Windows Update.

There, you will find an option called “Do not adjust default option to ‘Install Updates And Shut Down’ in Shut Down Windows dialog box”. If you enable this, then clicking “Shut Down” will just shut down your computer without installing updates. However, the “Install Updates And Shut Down” option is still available in the little menu, in case you need it