It could be corrupted. Have you run registry cleaners by any chance, they can cause this? You might also want to check for malware by running Stinger, RootkitRemover and perhaps also Malwarebytes Free - see the last link in my signature below.
If you decide to use Malwarebytes do NOT accept the free trial or else you will end up with the paid version.
Also after the above you may want to run the Virtual Technician as it can often fix things. http://mvt.mcafee.com/
If all the above fail to improve matters then uninstall everything in the normal manner, then run the MCPR cleanup tool, reboot and reinstall from your online account.
If that doesn't help, Technical Support is available free of charge by phone or online chat (24/7) via this link: http://service.mcafee.com/TechSupportHome.aspx?lc=2057&sg=TS