The restore points are probably the quickest, most likely to work method.
You can also check the event viewer, to see if it's logging any errors. It likely is. We could try diagnosing the errors, and fix each one.
You may also have a junked up registry. You can download ccleaner, and run the registry tool. You may need to run it several times to fix all the issues.http://www.piriform.com/ccleaner