Internet sharing - NDIS problem

I try to set up internet conmnection sharing across my two
networked Win98SE PC's.
But
1/ I lose my ADSL connection to the internet
2/ in System, the Internet Connection sharing network
adaptor has a yellow exclamation mark by it and the error
message:-
"The NDIS.VXD device loader(s) for this device could not
load the device driver, code 2."
This problem is covered in Microsoft'sKnowledge database
No 241255 and the answer is:-
"This behavior can occur if another program is providing a
Dynamic Host Configuration Protocol (DHCP) service for the
host computer."

The fix is to uninstall that program.

But WHAT program? How do I know what is a DHCP program?
Could it be my new ADSL modem? ICS worked Ok when I had a
dial up modem.

Thanks!

Will