Windows Service Printing Behaviour

Alright, I was tasked to develop a Windows Service that listens to a directory for files that are dropped in it, read them, delete them and print out a report.

I installed the service on my work laptop (Win 7 x86) and a test machine (XP x86) under a User account at first. It would do everything as it should except the print the report. No errors, nothing. Then I made it run under Local System and it produced a "No printers found" exception.

Converting the app to a Console Application and running on these machines gave the desired result. OK, so now I was assuming that there are security "stuff" involved.

Then I installed the service on a Server 2008 x64 machine (under Local System) and it j开发者_如何学Pythonust worked. Can anybody explain to me why this is happening? Why does the service allow printing from Server OS but not from a Desktop OS or am I missing something very obvious?

I'm guessing that the printers are installed locally on the server but installed as network printers on the desktop. Local System only have access to local printers.