http://support.microsoft.com/kb/q152104/ is titled "How to Prevent a Windows 95, Windows 98, or Windows Me Logon Prompt at Startup" and might very well contain the answer to your question.
Upon starting up my 98SE, I get a request (via box) asking for network name and password. If I hit cancel it goes ahead and starts up. I'm not on a network. How can I get this screen (request)to not appear. I believe its as simple as a check mark, but in my stupidity I can't remember where to go to uncheck. PLease help> Thanks