These aren't normal and should be taken care of immediately or you could lose a lot of important files. Its sounds like some viruses and spyware are programmed to mess with your registry. So, even if all seems normal and your computer is operating at a reasonable pace, you can still fall prey to hidden attacks that may give you that blue screen you fear and loathe. So just try to backup your files and install latest version of registry cleaner.It can make back up, clean up and defragment Windows registry the easy way .
_________________ XP Registry Cleaner