I am having the same issue....when I run the ipconfig command, all I get back is a single line :
Windows IP Configuration, no DNS or IP info at all. Looking for the cause of being unable to view webpages, IE says "cannot find server" even though the dialup network connection indicates connected, and I get the balloon that says "connected", and a data speed showing ....... I checked the tcpip.sys file.....it was there, I tried deleting it and, yes it did re-appear out of the OS, but still no joy!
Tried to reset the DUNS - TCP/IP using the netshell utility command,
http://www.modemsite.com/56k/duns-reset.asp, but got no log text output. Any ideas where to go from here?