check 4). quoted form http://www25.brinkster.com/ChicagoTech

How to fix corrupted IP Configuration
To fix a corrupted IP Configuration,
1) for Win9x, NT, ME and W2K, you may want to remove and re-install TCP/IP.
2) If it is win9x, you may try to run c:\windows\ws2bakup\ws2bakup.bat to
restore the original settings.
3) If you get "DHCP server unreachable" while using ipconfig /renew, you may
want to update the network card drive or go to NIC configuration to change
the media type matching the speed.
4) For XP, you can't uninstall TCP/IP (Uninstall is grayed out). You will
use the Windows XP command line utility netsh.exe to reset all IP-related
Registry settings to their default values. To do that, enter the command:
netsh int ip reset filename, for example, netsh int ip reset ipreset.t.xt
For more information, go to http://www25.brinkster.com/ChicagoTech

Please don't send e-mail or reply to me except you need consulting services.
Posting on MS newsgroup will benefit all readers and you may get more help.

Robert Lin, CNE & MCSE
Windows & Network Support, Tips and FAQs on
http://www25.brinkster.com/ChicagoTech
This posting is provided "AS IS" with no warranties.

"Karen" wrote in message
...
I am running win XP home edition and using T1 line to
connect to the network. I got a message says: " can't
listen on port 6515" when I try to get to the internet. I
also tried to type "ipconfig" at command promt, but it
says something like "Internal error has appeared.....".
Can anyone help me to resolve this kind of problem?

Thanks,
K