Here is something I ran across:
"If you need to buy time handsfree so it won't shut down, then start notepad and cut and paste the following in the notepad window:
@echo off
:loop
shutdown -a
goto loop
Save this to your desktop as stayon.bat, then you could double click on that to run while you d/l your updates."
I think you can also type shutdown-a with run command
hope it helps
-max