What can Services do under Windows?

Question

Does anyone have a good guide to capabilities of Windows Services under XP? In particular, I am trying to find out what happens when a program being run as a service tries t

Answer 1

Usually the service won't have permission to write to the window station and desktop, so it will fail; even running applications that load user32.dll can fail simply because user32 has initialization code that wants to talk to the window station and can't get access to it unless the service is running as an administrator.