3.1 is the about to be retired Debian stable. it was supposed to be retired in December of 2006, but some snags in the next release slowed things down, so it still runs.
I would simply suggest upgrading your Debian to Etch, which will be stable any day now. The problem is since you have no network on the machine, you can't just download the updates which would give you the driver for your NIC.
You have 2 choices, both of which involve some work.
1) Reinstall with Etch instead of Sarge. Since the box isn't online, you'd have to go back to the beginning. The Etch installer is found at http://cdimage.debian.org/cdimage/da...86-netinst.iso
2) The files that you downloaded are to make a kernel module, which will allow the card to work. You may need full kernel sources or at least headers installed to use the files you downloaded. Wasn't there also a README or INSTALL file included in the zip? You may be able to get those files on the machine, use a terminal to go into the directory, then try running as root:
That may install the driver, but if you don't have kernel headers or sources it may fail, and without network, you will have trouble getting the kernel sources.
I suggest doing the reinstall. It is a bit more work, but it is guaranteed to work.