windows service development

Hello everyone,
a brief description of the problem follows:
i have been developing a program(.net visual basic) starting in the form of a windows form(so as to control better debugging process) aiming to package it al last as a windows service. The curious thing with this is that the form version of the program accepts input from a shared folder(reads files from it) but the service doesn?t, although i ve tried execute it as a network service and stuff. If anyone has ever faced such a situation i would really appreciated it to learn whats going on.

Thanks in advance
Jim