Im having problems opening microsoft office programs. Whenever i try they just freeze but with Excel this only happened once - the second time it informed me about the problems experienced the previous time and asked me if i wanted to disable an add-in that was apparently the cause of the problem (i dont know what add-in). However, with the other programs it informs me of the problem that occured during start-up but does not suggest how i should fix it. What should i do?