Then it sounds like the problem is that your wireless card is not working at all. Your question made it sound like the card was working, but weakly. It is important to describe your problems precisely to get good help. When you say that the card works "barely, if at all", that is different from not working at all. The quality of the help you get will be proportional to the quality of your questions.
If you are used to Windows, Linux is not a "plug and play" system. Wireless especially can be hard to get working. Wireless is a problem for beginning users - it sure was for me. It is a fairly advanced topic, yet it is often the first problem you face since you need internet.
Do you know what kind of chip is in your wireless card? Do you know about ndiswrapper? It is probably going to take some work to get your wireless working in Linux. Since you are using Ubuntu (like me), a good place to start would be with the official and user supported documentation.
Do you have an ethernet connection available for this computer? That will probably work fine. But for the wireless, you want to find out if their is a Linux driver for it, and if not, whether it will work with ndiswrapper. If those don't work, you could try a trial with Linuxant, but that costs $ if you want to use it after the trial. But first find out what kind of chip is in your card (the brand of the card doesn't help on this point)
You can do a bit of research by reading some posts in the Wireless Networking forum here, under Networking. You can check the HCL (Hardware Comp. List) here to see if anybody else has got your card to work - although that is not a guarantee since the same model cards can have different chips.