I didn't want to start a new topic since I have a question closely related to the OP's:
I recently received a free Dell Latitude D820 with a non-functioning wifi unit. I have made sure the idiot switch is on and wifi is enabled in the BIOS, but it's not working.
I've installed the latest version of Ubuntu on it and am searching for a compatible wifi adapter--either express, pc card, or USB (the laptop has USB2.0).
Durrr. Here's the laptop's specs: http://www.dell.com/us/dfb/p/latitude-d820/pd?cs=28