Disable System Restore

You can gain a lot of drive space by disabling System Restore. (You should already have a backup regimen in place before you do this.) In Vista, right-click My Computer, select Advanced system settings, click the System Protection tab, and uncheck any drives. In XP, right-click My Computer, then under System Tasks, click on "View system information." Click on the System Restore tab and click the box next to "Turn off System Restore on all drives" to disable it.