Device installation and system restore
By default, Windows Vista always creates a new system restore point whenever a device driver is updated or a new driver is installed for a device. While this is generally best practice, it can result in lots of disk space being used for restore points if you often install and install new devices on your system. You can disable this behavior by editing Local Group Policy as follows:
1. Type gpedit.msc in the Start Search box and hit Enter.
2. Click Continue when the UAC prompt appears.
3. Navigate to the following policy location: Computer Configuration\Administrative Templates\System\Device Installation
4. Enable the following policy setting:
Do not create system restore point when new device driver installed.
Cheers, Mitch Tulloch, MVP http://www.mtit.com