This laptop was given to me by a friend and it was loaded with viruses including the winzip registry optimizer rouge anti virus. I used the prior knowledge I had to clean that out along with other registry issues and viruses. Yet, the laptop still runs really slow, and whenever the Pokki start button or bar is clicked, it freezes and the desktop vanishes. As far as I know, Pokki was preinstalled on here, and I know it's been used to replace the missing start bar in WIndows 8. What can I do to fix this thing?