How can I disable the restart popup after windows has installed updates?

You can prevent these automatic restarts from happening by performing a quick registry hack. This trick will work on all versions of Windows 8, Windows 7, Windows Vista, and even Windows XP. Windows will update normally if you perform this trick, but will not automatically reboot when you’re logged into your computer. You should still reboot after an update, but you can do it on your own schedule.

First, you’ll need to open the Registry Editor. Press Windows Key + R to open the Run dialog, type regedit into it, and press Enter

When the registry editor appears, navigate to the HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU registry key.

You’ll likely find that the last two parts of the key — the WindowsUpdate\AU parts — don’t yet exist. You’ll need to create them yourself.

To do so, right-click the Windows key, point to New, and select Key. Type WindowsUpdate and press Enter. Then, right-click the WindowsUpdate key, point to New, and select Key. Type AU and press Enter. This will create the correct registry key structure.

With the AU key selected in the left pane, right-click in the right pane, point to New, and select DWORD (32-bit) value. Type NoAutoRebootWithLoggedOnUsers and press Enter to name the new value.

Double-click the value you just created and type 1 into its value data box. You can then click OK — you’re done in the registry

You can now reboot your computer and your policy changes will take effect. However, you probably don’t want to reboot your computer! Luckily, you can make these changes take effect without rebooting.

First, open a Command Prompt window as Administrator. On Windows 8, press Windows Key + X and select Command Prompt (Admin). On Windows 7, open the Start menu, search for Command Prompt, right-click the Command Prompt shortcut, and select Run as Administrator.

Run the following command to make your changes take effect immediately:
gpupdate /force