A dial-up networking prob

PROBLEM
This computer connects fine through my network dhcp broadband server, but
when I attempt to connect through dial-up networking it seems not able to
receive dhcp information and thus has no setting for dns servers etc... and
all I can get is page cannot be displayed.

ATTEMPTED RESOLUTION
I have re-installed modem drivers, dun and TCP/IP half a dozen and have
scoured the MS knowledge base. my feeling on this issue is that DUN is not
re-installing new files OR telephony files are corrupted OR something in the
registry is wreaking havoc. It's a Lucent winmodem brand new.