Hi, I just installed Ubuntu on my computer and I can't figure out how to get my wireless device working. When I go into the networking tab, it doesn't recognize that I have the device at all but it does recognize the regular ethernet adapter (which I can't use). I have a D-Link 2340 USB adapter and my linux computer isn't hooked up to the internet at all. I have read that I should get ndiswrapper so I put that onto an external Hard Drive but I don't know how to install the applications. I need lots of help and don't know what I'm doing. Please help me!

First of all, welcome to LQ!
Secondly: to install a software in Ubuntu, use the Synaptic package manager. When you open it, press the reload button, so it will download the latest package list. After that press the search button, and type ndiswrapper. It will give some packagege out, like ndiswrapper-common, ndiswrapper-source and ndiswrapper-utils-1.9. To install the packages, click to the little box next to the package names, and select install package. After doing this press the apply button, confirm the selection, and wait. Synaptic will do the rest. After it finishes, the packages will be installed.
About ndiswrapper, I don't know anything, since I never had to use it, so I can't helo you with that. Sorry. Someone else will surely help you. You can also search the forum for existing threads, maybe you will find your answer there. Good luck, and happy Linuxing!

Thank you very much for your reply; however, there is a small problem. When I search for ndiswrapper, it doesn't come up with any results. If you can help me with this, then I have another question for you. I know that I need additional software for ndiswrapper and I have put that onto an external hard drive. How can I install those drivers onto my system?

go to this website, it worked for me
ubuntu ndiswrapper wiki