Here's how to get your Linksys working:

Open Accessories/Terminal and enter the command:
lspci
You'll get about 20 lines of output, one of them will identify the Linksys
adapter. For example, on my system:
03:07.0 Ethernet controller: Atheros Communications Inc. AR2413 802.11bg NIC
(rev 01)

"AR2413" is the important part of that line. Then I would Google:
ar2413 linux
and follow the links, especially ones which point to ubuntuforums.

The most common Linksys card is the bcm4318, which has a how-to here:
www.linuxquestions.org/.../how-to-for-\
the-bcm4318-airforce-one-card-473194/

It's probably helpful if you can briefly use a wired connection.


As for your actual question, if you can find a .deb file of a program you want,
it will probably install in Ubuntu. The only difficulty might be "dependencies,"
where you need to install libsomething.deb before you can install
application.deb.