Personally I would uninstall Photoshop, rename the directory if it's still there after uninstall, remove Photoshop leftover entries in the registry (make backup of registry first!) and /Program Files/Common files, do a scan disk, reboot and install Photoshop. If everything would work I would copy back the old plugin folder that is in the (old) renamed Photoshop directory. If the problem returns, then it's a plugin problem.
If you're technical like me, then you might consider to download the free
http://www.dependencywalker.com/ to see if DLL's are missing or any other errors (file/open and select photoshop.exe).
The event log might also give some answers.
And then there are dozens of other things you might try of course.
Question: what kind of operating system do you use?