Source of the dialup request?

My notebook users are experiencing a series of auto-dialing dialog boxes when logging on in an offline mode. These are Dell Latitudes running Windows NT 4.0 SP5 128 bit using TCP/IP only. I have configured a hardware profile with the “network disabled hardware” setting. It asks to dial in to (4) different NT 4 Srv & Wkst.

I have already searched (regedit) the registry for these names. There is no LmHost file either.

What is the cause of this and how do I find the culprit(s)?