You got Dell'ed.
Update, the Dell XPS now sees the esata hard drive. No thanks to dell, just googling web forums. Here's how simple it was, apparently this is a common Vista 64 issue, go to device manager>disk drives> right click "scan for hardware changes". JACKPOT!!!!
No why the F*ck couldn't Dell tech support have me do that? Instead they sent a know nothing parts changer to my house and changed the entire motherboard. Then after that went all the way to the floor supervisor in India who was so panicked he gave me his email and private telelphone, he eventually gave up too and sent the paperwork for a refund.
But I'm going to stick with it for the moment, NOW......
I'm trying to get the XPS to recognize my 1394 hard drive, the same trick didn't work for it, Esata good, firewire still bad. Any suggestions?