I've got (what I believe to be) a fresh installation of Server 2003 R2 (SP1), and while I've got perfect LAN connectivity, I can't access the Internet. I've tried pinging websites through Command Prompt, and I still get nothing. I've never used Server 2003 before, so I've got no idea what to look for. This box is plugged into the same switch as the computer that I'm typing this up on, so I know it's not that.
I checked, and I don't think that this is a dupe of this question, as I am about 99% sure that someone installed Server 2003 on this box then never used it - I doubt that it ever had internet connectivity to begin with.
EDIT: Apparently, I've got basic network connectivity now... I can ping the router at 192.168.0.1, but I still can't connect to the internet.