Yours will be an Intel Adapter not a Dell Wireless one:
http://ftp.dell.com/Pages/Drivers/xps-l502x.html#Network
Check what the hardware IDs of your wireless card and Bluetooth adapter are to do this get to Device Manager by pressing [Windows] and [ e ] then select properties then Device Manager. Right click the unknown device or network cards and select properties then select details and hardware IDs.
see Windows Reinstallation Guide/page 124 (bottom half) - 125:
http://philipyip.wordpress.com/dell-community-forums/