Activating file sharing causes NetDi.dll error

Hi,
When I go to Control Panel->Network, I see that File and
Print Sharing is not listed. I need to be able to share my
files with an XP computer.

I select Client for MS Networks in the list, and then
click the File and Print Sharing button, check to give
others access to my files, and click OK. Then in the
Select Network Service window, where File and Printer
Sharing for MS Networks is listed, I select it and click
OK I get a Rundll32 Illegal Operation message. Details
shows that the error was in NetDi.dll.

If I click Have Disk instead, I cannot find the file it
wants on my Win98SE CD or in the C:\Cabs folders.

I have extracted and reinstalled NetDi.dll, but that
changed nothing.

Any clues?

TIA
Duncan