I have a Dell Vostro 2520. It came with pre-installed ubuntu 11.10. Wireless networks were working fine until I installed Broadcom STA drivers. After that I tried many things but my wireless still didn't work. So I installed ubuntu 12.10 using erase 11.10 and install ubuntu 12.10 option. Still my wireless networks are not detected.
rfkill list all 1: hci0: Bluetooth Soft blocked: no Hard blocked: no sudo lspci -nn | grep "BCM" 07:00.0 Network controller : Broadcom Corporation BCM43142 802.11b/g/n [14e4:4365] (rev 01)
There is nothing shown related to wireless LAN