Have you been doing some cleaning of the programs on your computer? If so this is probably the cause. There is a program called CCLEANER
Uncheck the items in windows and applications then select issues put a check in everthing then scan and then fix. Then go back to windows and check all under internet explorer and windows explorer. In system check Temp files, clipboard, memory dumps. Check everthing under applications. And uncheck everting in issues. Analyze then clean.