System restore has always been buggy. When it works it's great, but I refuse to depend on it. Here are some alternatives. The first two are to backup the registry. The third is as comprehensive solution.
1) Click on START - RUN and type: Regedit (press ENTER). On the menu bar click on file, then export, choose where you want to save it, then enter a name for it in the box titled: File Name. At bottom put a tick in "All", then click on save. If you ever want to restore the saved version, just IMPORT it.
2) The best way to backup the registry, in my opinion, is to download and run ERUNT. It's the best registry backup utility available - and it's free.
3) The best of all options is to use disk imaging software on a regular basis. The best such utility is Acronis True Image, but it's not free. The best free alternative is Macrium Reflect.