Can't access MS Client, Protocols, Services, etc.

I have a customer running Windows 98SE. He was getting an error message
related to MSHTML.DLL when starting his computer. I was able to re-register
MSHTML.DLL and reinstall Internet Explorer to remove the error messages.
Now, I'm trying to configure the computer to get back on the network, but
when I try to add MS Client for Windows, any Protocols, etc. the program is
not responding. I can click on the "Add" button, but when I try to select
"Client", or any of the other options, there is no response. I have run
System File Checker, and reinstalled the files associated with the various
clients, protocols, etc., but still no response.

Does anyone have any ideas? I've never seen this sort of behavior. I have
run SpyBot, Ad-aware, Spyware Doctor, and Norton Corporate anti-virus
without any problems. I've run Scandisk (Thorough) and nothing seems to
correct the problem. I'd like to avoid reinstalling Windows 98SE and all of
the applications like Office 2000. I've used "msconfig" to load just the
basic startup programs.

Thanks for any help you can send my way.

Joe G.
Dearborn, MI