WinXP Issues - Virus?

[Guest]

I work for an ISP. We have seen multiple winXP users having the same
problem. We have them connecting into CIsco 5400 via Dialup Networking
connection. They establish a connection and obtain IP. They are unable to
get web pages or email. Outlook Express returns "host not found" when host
name is specified for mail servers, if we use IP's for mail servers Outlook
Express returns TCP/IP error. I can ping their computer from ISP fine. They
can ping by IP fine. PIngs to domain names returns "host unreachable". I
have tried auto obtain and specifying DNS. They can ping DNS fby IP fine but
nslookup returns "server unreachable". I have tried reseting TCP/IP with
netsh command. Browser is unable to open web page by IP or domain name. I
even had one of our customers with this problem connect into their RCN cable
account with same symptoms. ANother customer started experiencing this
problem directly after both Norton and Ad-aware removed some files. The
majority of computers with this have updated Antivirus and system scan comes
back clean. HOwever, one user experiencing this came back with a virus but
he could see it in his processes taking up over 90% of CPU. All other
computers lack this. Please, any help would be appreciated. I think this
may be caused by missing DUN files? Any way to restore DUN wihtout using
system restore or reinstall of winXP? Help greatly appreciated, thanks.

 

[D.Currie]

Have the delete tpc/ip in networking and delete dun. Reboot, then reinstall.
Don't just let it add back tcp/ip, make sure it reinstalls it from the CD.

If that doesn't work, I've seen the same sort of problems with systems that
have had the firewall get corrupted.Uninstalling that isn't easy, as you
have to poke through the registry and delete a lot of entries. A regular
uninstall from add/remove programs usually doesn't do it well enough.