Start system restore and tell it you want to do a system restore. It will let you choose from the whole catalogue it built up since you last cleaned it. Count them and you how many it are.
The two ways to get rid of them:
1. Disable SR (removes all) and enable again (makes a new one).
2. From Disc cleanup wizard: delete all but the last one. Never done it myself, but I've read it here.
Windows XP media center 2005. How do I find how many restore points are saved, and if thier are too many, how do get rid of them?