Dell restore disks, need help!

Hi,

I have a Dell XPS 400 that I purchased years ago, and since have built me a new computer and gave this one to my wife. Well this computer is now riddled with viruses, and even trying multiple programs (Maleware bytes, AVG Free, SuperAnti Spyware, Avast, Ec.) I have not been able to clear off all the viruses and they keep reappearing. Also when I try and go into safe mode my computer goes into a blue screen. She really messed it up lol.

Anyways, now im kinda in a predicament. I looked all over but I do not have the restorations disks that came with this computer, and upon calling dell, they said my service has ran out for them to help me for free and want me to pay then 50-60 dollars for a new disk.

So now im wondering if there is something else I can do? I tried to find torrents that had this particular disk, but the couple .ISO files I download and used them, they wanted me to enter a CD key, which I don't have. So now im stuck, is there anything else I can do? I really don't want to pay 50 dollars for a restore disk.  

Here is one of the .Iso torrents that I tried to use. Not sure why its asking me for a CD key though since my key should have been pre activated since its a dell disc and a dell computer.
http://thepiratebay.org/torrent/4410910/Windows_XP_Home...