I've used the NTSVC.OCX, and here's some tips:
1) It's unsupported code -- don't call Microsoft if you have any problems
2) Don't attempt to debug the service code - VB will GPF on you. Set your breakpoints some point after the service code.
You may want to contact Desaware, they sell a product that does this (you'll be able to get support if you have questions).
Chip H.