Microsoft Network

I recently inherited an IBM Thinkpad(model A20m)running Windows 98 and everytime it boots I get a Microsoft Networking dialogue box saying “No domain server was available to validate your password. You may not be able to gain access to some network resources.” I click on “OK” and I get another dialogue box asking for User name, Password, and Domain. If I click “Cancel” it boots fine. It’s getting really annoying getting these dialogue boxes everytime it boots. Does anyone know how to stop this laptop from trying to access the network on boot? I’ve already looked in Start-up and MSCONFIG but I don’t see anything that looks like it’s causing this (I might be overlooking something though)?