Restore Factory Settings

Hello,

can somebody please give me some advice, I have an Acer Aspire 5610 and it got infected by a virus, i removed it with AVG but the computer still remains slow and freezes constantly, i tried system restore and that didnt work so i thought i would restore the laptop to its factory settings. The problem is, i cannot workout how to to do this, having looked at various forums, i have tried alt F10 and this does not work, F2 takes me into the Bio menu and F8 brings up the safe mode menu, i just cant find it, i dont have a recovery disk, as i didnt get one when i bought it.

Can somebody please Help!!!!

Regards
Steve