Recently I installed Ubuntu on my windows machine using the latest Wubi installer and ran into an issue getting my Dell XPS M1530 laptop's wireless adapter up and operational. My particular flavor of the M1530 uses the Dell Wireless 1505 Draft 802.11n WLAN Mini-Card wireless adapter. This adapter is built on the the Broadcom 43xx series of chips (in my case the Broadcom 4328) and unfortunately these devices don't work with Ubuntu 10.10 out-of-the-box.
To fix this, grab an ethernet cable and get on the your network the wired way. Pop open a terminal window and run:
~$ sudo apt-get install bcmwl-kernel-source
~$ sudo modprobe -r b43 ssb wl
~$ sudo modprobe wl
This should get the wireless adapter up and running and now you can use these instructions from the Ubuntu forums to connect to a wireless access point.
Hope this helps.