Help!! cant receive packets windows XP sp3, command prompt not working

Hi everyone, really hope you can help me out with this, i have been given a friends toshiba satellite to fix after it had multiple infections from fake antivirus software. It all seems clean now but I can’t receive packets through any network connection and when I try and run anythin in the command prompt like a ping or ipconfig command it just freezes and i end up having to ctrl-alt-del to get out of it. IE is also not responding…HELP!!!!!