Disable System Restore (Protection) in Vista

Source
1. Click the Start button.
2. Click Control Panel.
3. Click System and Maintenance.
4. Click System.
5. In the left pane, click System Protection. If prompted, enter your Administrator password or click Continue.
6. Uncheck the box next to the disk on which you wish to disable System Restore.


7. Click OK.
Note: Disabling System Protection will delete all existing restore points. To re-enable the System Restore Utility, follow the steps above, but check the box next to the disk on which you wish to enable System Restore.