Welcome to Bleeping Computer, tom30nl
Personally, I don't recommend registry fixers, cleaners, or any other similar programs to most users. If you are an advanced user, and you know exactly how to get out of a difficult situation with your computer, there may be a particular need for a registry tool. With that said, you are already in a difficult situation with your computer, and you need a solution.
Do any of your icons work? What is the exact error message that you get when attempting to click on an icon? What spyware detection programs are you using?
If the XP system restore didn't work, you could try to run the XP System File Checker(SFC). Please see this mini-guide -How To Use Sfc.exe To Repair System Files
Whenever you are in a situation like this, I would recommend that you back-up any data that you may require if your computer becomes unusable, or you get to the point where you have to do re-install. A re-install should only be attempted after you eliminate all other possible solutions.