purchased a laptop from a friend, it is running Vista, short story he cleared all his personal information of including anti-virus etc, i tried to load avast anti-virus and it froze, turned it of and now wont load up just get the Microsoft bar thing going then Blue screen of death, any ideas how to get in to do a system restore etc....

 

its one of the F buttons, i think mine's F5 my mates was F10.
you have to tap one of them when you turn on your lappy then it wil bring up control bit.