Another possibility is to turn off System Restore. Most of us don't restore anyway - we just reinstall everything. I've seen huge system backup data in the System Volume Information folder in some people's computers.
For those who regularly screw up their system drive and reinstall very often, Norton Ghost or other similar backup software is invaluable. I use the DOS version of Ghost that came bundled with a motherboard.
I install the OS, drivers, apps and utilities. I set up everything ready for use exactly the way I want them - printer settings, word processor settings, download settings, file associations, internet connection, desktop shortcuts, registrations and validations, etc., etc. Then I make a Ghost image of the system partition.
It takes a lot of patience, but it's worth it. Whenever I want to reinstall everything, which is roughly once every three to five months, I just restore it from the Ghost backup and it takes less than 10 minutes.
After that, I just need to update my anti-virus and some vital utilities that have had newer versions released. Then I make a fresh Ghost image for the next time, and that takes another few minutes - say half an hour to one hour total for a process that would take several hours if done from scratch.