I have a 2.5 year old Compaq Presario 900. Recently it takes forever to startup because it hangs midway. Then I would have restart it again and again and again. When it does reach to the main screen, it'll hang again, but when I tap the front hard enough, it'll unfreeze. Sometimes it'll stay ok, but most of the time it freezes after it unfreezes. Please help. Does anyone know what's wrong with it? Thanks.