Yeah, It was a little extreme but all kinds of weird things was happening to my system and a system restore messed up the cs4 install so I had no choice. However, afterward, everything was fine as there were no conflicts between previous drivers ( especially nVidia ) which usually compounds issues.

BTW, the old nVidia drivers need to be completely uninstalled before installing the latest version - Do not install new drivers over the top of old as you will have problems.