Jason, BBW, Baked Alaskan: Thanks for the tips and help. I've fixed the registry problems (through Registry Doctor), and it was a mess.. but still the screen freezes so that was not the problem. I'm login to the internet through a putty-tunneling-connection, I am thinking that may be the case (but otherwise, my LAN seemed to be down ever so often and have been lazy to set it back - i guess I'll have to give that a try also!).
Registry Mechanic, small programm that fixes some problems and asks for registration to fix the remaining ones. Good thing is that it identifies the exact location, so that you can fix them manually later on. For anybody interested in such things! :-)