Scenario:

Windows 8/10 has initiated the process to install patches and updates but needs to restart. You will receive a banner message box with text such as this:

Restart in 14 minutes, 59 seconds

Your PC needs to restart to finish installing important updates.  If you've already saved everything, you can restart now.  Otherwise, you should take a moment to save your work.

A restart is needed

To finish installing important updates, you need to restart your PC.  If you've already saved everything, you can restart now.  Otherwise, you should take a moment to save your work.  Your PC will automatically restart the next time you sign in.

Solution:

You can use the group policy editor to disable this behavior (you will still have to restart at some point to finish installing patches but it won’t happen automatically). Steps for professional and higher versions of Windows that have the group policy editor included:

1. Open epedit.msc
2. Navigate to “Local Computer Policy”->”Computer Configuration”->”Administrative Templates”->”Windows Components”->”Windows Update”
3. Click on the “No auto-restart with logged on users” policy and change it to “enabled“

Steps for home versions of Windows that don’t have the group policy editor.

1. Open the registry editor, e.g. start “regedit”.
2. Navigate to KEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate\AU
3. Create a new DWORD (32-bit) value and name it NoAutoRebootWithLoggedOnUsers. Set the value to “1” (with no quotes).
4. Reboot the computer after you have entered this.