This technique works on Windows XP Professional SP1 and above for sure.
If you do update your windows regularly, and are annoyed with the ‘Do you want to restart now’ prompts which keeps recurring every 20 minutes, read on.
This is a nuisance while playing games, and while watching movies (for me )
There is a simple solution for this :
1) Go to Start –> Run
2) Type gpedit.msc . This is the Microsoft’s group policy editor.
3) You should see a screen like the one below
Select Administrative Templates under Computer configuration then
windows components > Windows Update
In the right pane look for Re prompt for restart for scheduled installations. Double click.
In the options. Select disabled.
Now play or watch movies in peace.
Errata : Disabled prompts every 10 mins! Use enabled and make the interval 1440. Thats the maximum interval between prompts.