Laptop Restore

Hi guys, I have a problem with my friend's laptop. Her little girl was given one by the school and a few months later its full of viruses. After having a look we decided to try to restore it to its original settings. Of course the problem now is no one can remember if it came with any recovery discs. I come to the Dell site and tried to follow the steps where we perform the factory image restore.. F8-> Repair, etc.. But I can't even type "administrator" into the login field. The only option is Student. When I go in that way there's no option for Dell Factory Image Restore. I'm at a total lost now. Between the two of us there's no discs nor image I can locate. Is there any way to fix this? Its running Windows Vista.