Sometimes Windows Updates need to restart the computer to finish the installation. Before SP2, Automatic Updates would not restart your computer automatically. But this is not the case with SP2.
I've lost many downloads overnight for a few times and I can't stand this any more. Follow the below instructions to disable the auto restart in Windows Update:
For WindowsXP Pro users
- In the Start Menu go to Run type “gpedit.msc” and press Enter
- Now a Group Policy editor will open. In this window navigate to: Computer Configuration -> Administrative Template -> Windows Components -> Windows Update
- Double click on No auto-restart for scheduled Automatic Updates installations
- In the settings window Choose Enabled and click OK
- Close Group Policy Editor
For WindowsXP Home users
- Go to registry editor and navigate to the following registry key:
- HKEY_LOCAL_MACHINE \Software\Policies \Microsoft\Windows \WindowsUpdate\AU
- Change the “NoAutoRebootWithLoggedOnUsers” DWord value to the required number.
0 = False (Allow auto-reboot)
1 = True (Disallow auto-reboot)
The next time Windows updates your system it will not restart the computer automatically, but will notify you that restart is needed in order to finish the installation.