I have installed 12.04 on a dell vostro 2420 (previously 11.10) and wifi is gone now but wired network remains. I've reviewed the other questions and tried some stuff but no luck yet. The following is the process so far so hopefully someone can help:

After installing 12.04 using the additional drivers utility did not bring up any proprietary drivers and using synaptic on installation then reinstallation of bcmwl-kernel-source and b43-fwcutter does not help bring up any drivers either (tried rebooting after as well)

I have made sure in the bios that the wlan is turned on, and it appears the laptop does not have a wireless hardware switch, only the keyboard function shortcut which turns bluetooth on and off on the taskbar but there is no lightup of the wireless function on the laptop itself.

Dell does not appear to have any drivers for ubuntu and google does not appear to be much help :(

Thanks in advance!