Get CCleaner (Crap Cleaner) from Piriform. It's free.
Has a "Registry" tool which will scan the registry for "junk" entries which then can be fixed - (deleted).
Junk would be orphaned file extensions, unresolved references, etc.
I run once a week to keep the registry in shape.

It's not the computer, it's the software being stupid.

I've been using in for several years now. Started with a Canon A590 then a Canon A810. Used for time lapse and motion detection sessions. You use scripts to accomplish a task such as photographing lighting (motion detection script). I have never had anything "bad" go wrong. You boot CHDK from the SDHC Card and if for some reason you lock up the camera just power off and start over. Learning curve can be steep because of all the options. I was amazed the first time I waved at the camera and it took my picture, that hooked me.