Are you saying that the contol panel opens but clicking on any of the buttons does nothing, or that the contol panel will not open?
If you type "control" in the run box this will open the contol panel if it's working.
By searching for "*.exe" files you can run the applications with out opening the panel. Make sure you know which programme it is that you are running.
Have you tried running "sfc" system file checker. This would tell you if any files are corrupt.
Could this be a virus? Are you running any protection programmes?