I just installed ubuntu 11.10 on a dell inspiron 1501 with a dell 1390 broadcom internal wireless card. Had lots of problems.

I finally found this:

https://help.ubuntu.com/community/WifiDocs/Driver/bcm43xx

Worked miracles.

...i aint nobody but a noobie but have had same/similar probs -- Linux Mint 11 (not 12) 32 or 64 bit works GREAT (love MINT11) on old gateway mp8708 winxp and newer dell n5010 i5. best luck when "create new wireless network" used to set up (sometimes had to set up more than one time before it stuck, but...).

best to you!

Dell usually uses Broadcom based wireless chipsets in its laptops. The driver can likely be found here: http://www.broadcom.com/support/802.11/linux_sta.php

You may have to build the driver from the files provided by Broadcom using the instructions provided and install it. Alternatively, ndiswrapper could possibly be used as well - using the MS Windows XP driver for the wiresless card.

Try Linux Mint. That's what I did when I hit this problem 18 months ago. I started with Mint 7 and am now running Mint 12 on my Dell Inspiron. No wireless problems

To answer your question we will need more information. It sounds like the driver for your wired connection is not in the linux kernel, so we will need to know what wired card is in use. I highly recommend moving this discussion to the forum so we can guide you through the detect and possibly configuration steps.