Hey no problem. You might as well set up machine with a dual boot win 7 and xp // not nearly as conv but definitely do able. Be a good way to test keys :)
Sorry I could not be of more help.
Good luck.
Here is a good link to get set up with XP on dual boot:
http://support.dell.com/support/downloads/driverslist.aspx?os=WW1&catid=-1&dateid=-1&impid=-1&osl=EN&typeid=-1&formatid=-1&servicetag=&SystemID=PREC_T3500&hidos=WV64&hidlang=en&TabIndex=&scanSupported=False&scanConsent=FalseDells 32 biot XP driver download page
Robert