By default all Windows 2003 Servers are configured to automatically
install Windows updates and reboot if needed. Typically most servers
are set to reboot between 2-4 AM CST. If you would like to modify the
time at which your server installs and reboots for Automatic Updates
you can follow these steps.
Log into your Windows 2003 Server via Remote Desktop with your administrative login.
Select Start -> Control Panel -> Automatic Updates

You can use the drop down to select the time wish to reboot the
server at. Please keep in mind that the servers are in Central Standard
Time (CST) and you may need to convert your time zone into CST to
decide the optimal reboot time.
