If the Network Card does not show up in the Device Manager that usually means that the BIOS is not reporting it to Windows XP, check the BIOS, usually F1 or F2 immediately upon bootup.
Good Luck, I don't think you should buy a MAC, but I wouldn't buy a DELL either.....LOL
Fedora Core Forever More
I just put on my magical Red Hat, and all my troubles go away.