Sounds like you have something running at start up that is reinstalling these items. A virus or sypware. Try installing the following Anti-Spyware programs, boot into safe mode and run them.
The home of Spybot-S&D!
Ad-Aware 2007 Free - Lavasoft

If that doesn't take care of it you may need to find them manualy with a process scanner type of software. I would try this next.
HijackThis
Merijn.org
There are plenty of places to help with the results of HijackThis too.