I created a 12.04.3 LTS Ubuntu DVD per website instructions. I ran it on my Dell Inspiron M5040 laptop in "Try Ubuntu" mode and it worked well. Specifically, it readily detected available wireless networks and allowed problem-free connection. In the networks pull down menu the check/toggle link for enable wireless connections appeared and worked. I could also manually toggle back and forth my keyboard FN-F2 key combo and the wireless would toggle off and on as expected.
I then installed the Ubuntu to the computer. Everything seems to work, except, the computer now does not detect wireless networks. The pull down menu no longer has the check/toggle link for enable wireless networks. The FN-F2 key combo for toggling the wireless reception on and off does not work, it only stays off.
I my initial effort was with the 64 bit version. I later tried all of the above with the 32 bit version with exactly the same results.
I read another article on here about getting some proprietary support software from the wireless chip/card manufacturer (Broadcom?). However, it seemed to me that if all worked well while Ubuntu was booting from the trial disk, then somehow it must have been accessing all the necessary software/drivers it needed. However, I am very much a computer novice and am not certain about this leap of logic.
Can anybody help me?
thank you for your kind offer to help, Chili555. I figured out how to open terminal, followed your instructions, and got the following response (quotation marks mine):
"03:00.0 Network controller : Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller [14e4:4727] (rev01)"
Thanks again for your offer to help. I look forward to further help.