name resolution/lookup suddenly stopped working

[Anon]

Windows 2000 Pro client with SP4 was working fine and all
of a sudden all DNS lookups from applications have ceased
working. I can use "nslookup" from the command prompt and
still resolve dns names OK, but every gui app (web
browsers, ftp clients, email clients) now fail to resolve
hostnames. No software changes, or networking config
changes have been done to this machine. It just abruptly
ceased resolving DNS. The DNS server in my network is
working properly, evidenced by a dozen other client
workstations (XP and W2K) are all still resolving DNS just
fine. Is it possible this machine might have picked up some
kind of trojan/spyware via the I.E. web browser that is now
intercepting all winsock DNS lookups and since the internal
network is behind multiple layers of NAT and firewall, that
malware cannot phone home or something like that? Or am I
just being paranoid.

In googling for answers, I've read similar cases of sudden
lost DNS resolution happening in W2K and XP, that the
owners of these machines have only been able to fix their
machines with a re-install of Windows. I really don't want
to have to do this.

 

[Richard G. Harper]

If it's just the one client having problems then I'd be suspicious that
something unwanted has indeed crept into that system as you suspect. Try my
process for isolating and cleaning unwanted pests at
http://rgharper.mvps.org/cleanit.htm and see if it helps.

 

[idehao]

not a biggie...search for a winsock fix for windows 2k pro..and u'd b
set, might involve "just" deleting winsock keys and re-installing the
rather than a complete system restor


-
ideha