Old Server is being a pain

Hello all,

Recently upgraded our domain to windows 2003 server. New domain controllers, ect…

I have an older Windows 2000 server machine that is still in place doing some minor things, I have not removed AD from it yet.

Setup: About 15 PCs connect to a switch. the switch into a Linksys Router, then into the DSL.

Problem I am having is, when I reboot this old machine, no one on the network can access the internet. I dont know wheather it has some sharing thing somewhere deep down, or if it still thinks its the top Domain controller or what. I have searched high and low on this machine and cant seem to find anything.

Please Help! Thanks in advance.