Yay for LifeHacker (again).
- Start menu
- Select Run
- Type gpedit.msc, hit enter
- Select and open folders:
- Local Computer Policy
- Computer Configuration
- Administrative Templates
- Windows Components
- Windows Update
- Double click Re-prompt for restart with scheduled installations
- Select Disabled then click OK
Only supported on Windows 2003, XP SP1, 2000 SP3