you have alot of choices to fix this problem :
1 - download tuneup utilities 2007 or 2008 will fix your registry and solve 90 % of its problems .. then try some good anty virus "kaspersky is suggested " to clean your PC . (there is a youtube video about how to use it) works on windows , MAC and linux , special edition for each or similar solutions
2- go to run.exe and type msconfig chose start up and uncheck everything except ctfmon and your antivirus system "you can keep msn to make it auto lunch <------ unwanted untell you fix your problems" for windows . this is not a problem in MAC and linux to have something to fix it
3- if you couldn't do those steps due to dizzy process repeat them on safe mode .. restart your system and keep pressing f8 to show safe mode minu . for windows
4- use your recovery CD to end your nightmares and have a fresh copy of you operating system
Hope these steps are usefull .. i gave general steps for refreshing you machine even you only need windows steps coz these bugs mostly show up in windows and almost does not exist in other O/S