About a week ago my I nocticed that when every I tried to watch a flash video (with the exception of using Chrome) I was asked to install flash player with I already had installed. However if I reinstall it everything works until I restart my PC. Needless to say the is getting frustrating but I can't seem to fix it. I have tried uninstalling and reistalling but this doesn't help... Once I restart the computer it doesn't work. Any help would be appriated.
Edit: Forgot to mention I'm running Windows 7 (64 bit).
Try a clean install as described in http://forums.adobe.com/thread/928315
If the problem persists, run the uninstaller again, then try fixing the permissions on your system: http://forums.adobe.com/thread/987370