You can check if your BIOS has any information on the wireless card installed.
From start menu you can run
msinfo32 press enter. Then go into
Components>
Network>
Adapter and see if there is anything in there.
But after looking at the site a little harder the only (WLAN) Drivers for Windows 7 was this one.
Broadcom Wireless LAN Driver Windows 7 (32/64) 5.60.48.35
Download
Unless you have a WiMax but I think you would know if you did.
You can also probably remove part of the back and access the Wlan adapter. I dont know exactly which area it is in though.
If the Broadcom doesnt work try this one.
Atheros Wireless LAN Adapter Windows 7 (32/64) 9.2.0.419.0
Download