Try with a supported OS: XP 32. It may well be caused by the 64 bit version.
A link with many ideas about computer setup http://forums.adobe.com/thread/436215?tstart=0
Computer DETAILS are always good to provide
Work through all of the steps (ideas) listed at http://ppro.wikia.com/wiki/Troubleshooting
If your problem isn't fixed after you follow all of the steps, report back with the DETAILS asked for in the questions at the end of the troubleshooting link