The service is running under a user-id, not LocalSystem. When I use the same user-id to login into Windows XP, and run the same program in a Command Window, it works flawlessly.

I also have 3 other programs, which do the same thing using essentially the same code, and which run fine both in a Command window and as a service. They all call the XML parser to parse the same file (a common XML parameter file).

I also use the same 4 programs on a number of other Windows XP machines, where they all run fine in console mode and as services.

That's why I'm puzzled.