And there's the defensive post. So typically depressing....
Man, I should get my meds filled right now so I can make it through the day. I'd hate to live in an area where even the best tech formats for this kind of thing.
I don't know what "bootleg Win 7" means, but I guess I'll start giving some real help before you get red in the face like everyone else and start calling me names.
You only asked if it COULD be caused by software. The answer is "Yes". It could also be a hardware problem. As mentioned before, we need to know if it was getting a proper IP address. If it's a 169 address, that's not one and it means that Windows can't get an IP address from a DHCP server, so it assigned itself one.
If it's getting a valid IP address (maybe not on a typical lan range, because it's plugged directly into the modem) it's more than likely software. It could be a DNS issue, as suggested. It could also be remnants of a firewall left behind, a corrupt tcp/ip stack, etc.
Part of the reason your thread depresses me is because you asked a simple question with a simple answer, but clearly there is a bigger issue that you want us to tell you what to check. To me, that's not cool. You really should be researching (so that you learn!) and asking for us to help you with specific understanding of something, or helping with a more specific issue.
Please don't get mad. Just report me if you feel like I'm being offensive and not helping, then go about your day. (I've said this so often that I think I should just make it my signature...) I really am here to help, but it's just so darn depressing sometimes.