Password problem

From: Yaacov Klapisch - RCS (yaacov_at_rampal.com)
Date: 08/22/05 

Date: Mon, 22 Aug 2005 19:58:42 +0200

I have two computers connected with a lan.
One is Win XP Pro and the second is Win98SE.
The XP Pro logs with user Administrator and the system did not ask for user
and password.
The Win98SE uses a program that connects to one of the XP folders on a
simple share.
Everything was working fine till someone decided to share the internet
connection of the XP on the Win98SE.
After trying many things that did not work I am left with a Won98SE that
cannot connect to the XP. I am asked for a password that I don't know. There
are no passwords whatsoever on the XP machine. A user called User1 was
created and I cannot even delete it. Also I cannot remove the logon window
when windows start.
Is there a way to revert this to the previous configuration?