I just have a couple of quick questions about installing my ethernet card that will take a few minutes. This happens from time to time. Make sure to check the obvious things like your connections. The ethernet cables should click when it attaches to your computer and to the wall outlet. Make sure the cable is an ethernet cable and not a regular phone cable.
Ethernet cables are about twice the size, most noticably at the ends.
If your roomate has a computer that is working properly you might also want to try plugging thiers into the port you are trying to use. Sometimes, but not often it is the wall jacks themselves which are bad. After you have done all of this, you may want to start the process over after undoing past installations. Make sure that you remove your ethernet card drivers so that you can really start again from scratch. Repeat the installation, carefully read and complete each part.