Error 51 - The specified computer is not receiving requests

[marty39]

Some time during the last day or two (May 11 to today, May 13) the
Windows XP Home computer began giving the following message to Windows
98 SE computers on my home network:

Error 51: The specified computer is not receiving requests. Make sure
you are specifying the computer name correctly, or try again later
when the remote computer is available.

It gives this message in response to NET VIEW commands and to a daily
scheduled NET TIME task. A printer attached to it is offline and can't
be put online. But the computer responds to pings and can be seen in
Network Neighborhood.

The only computer on my home network that can access the Win XP Home
computer without any problems is a Win XP Pro computer.

I turned the Windows Firewall off but that didn't help. The Control
Panel applet for Add or Remove Programs says the latest Windows update
was April 18, so unless one of the updates had a delayed action the
problem can't be caused by security updates. The home network accesses
the Internet throught a wireless Internet router with DHCP and NAT,
and the XP Home system is protected with BitDefender Antivirus 2009. I
did edit the Windows Registry recently to correct the default email
client application, but I wouldn't expect that to affect network
access.

Please help.

[marty39]

For what it's worth, Microsoft Helped and Supported. The trouble
disappeared after I ran the automatic fix from "How to reset Internet
Protocol (TCP/IP)," Article ID 299357, on the Microsoft website.

It made some changes in the Windows Registry that of course I don't
understand. I had previously been troubleshooting a problem with
computers on the local network not showing in Entire Network and that
might have introduced some errors. By the way the original problem was
solved by shortening and removing all spaces from the comments /
descriptions in computer identification for each computer on the
network.