Turn System restore off in Control Panel>System>System restore tab by taking the ticking the relevant box. Restart the computer and that gets rid of all the useless Restore Points you already have. Take that tick out and move the slider so you have only 5% of space taken up, click Apply and OK then choose System Restore from the Start>All Programmes>System Tools menu and create a Restore Point of your own.
Let things run for a day or two and try to restore back to that point and if that fails, you have a problem so post back for details on running the System File Checker.
Well, I'm having some weird problems right now that I really can't explain, so I really wanted to go back to previous restore point, not one created presently or in the future. But going forward after I fix this situation I'll try that.