"What OS does your friend run?
A quick google search got me a Tweaking post that might get some more performance out of your Borderlands, but looking at your specs there is something seriously wrong if you can't run Borderlands.
Have you tried posing your question to the official Borderlands site?
My friend has Windows 7, but this shouldn't really matter should it? I honestly don't know.
Ah well, I'll go post on the Borderland forums like you mentioned. :-) Thanks.