Ah the age old frustration of VB6 programmers!
Yes, you can build a Win2K service. You need to download the NTSVC.ocx from microsoft or use the RunAsService service to kick off your program. HOWEVER, I don't recommend it. VB6 services tend to leak memory and require frequent reboots. What is more they don't integrate with MAPI well (though recently I have found it can be done). If you really want to build a win2K service, go to
VB.Net. It has special libraries for it.
Yehuda