Navidad Trojan Removal from NT Systems

I hope this is the right place to start this discussion. I searched for information on this Trojan with few results. Our client has 250+ systems and this Trojan has surfaced it’s ugly head. Using a registry Undo file (UNDO.REG) from McAfee website Windows 95 systems are ok. Although we regain control of the system NT still respondes (on boot) that it can’t find the WINSVRC.EXE file. Clicking OK allows the system to start and run. Any ideas on how to correct this?