My exe runs fine by itself, but does nothing when loaded by a service

Question

Simple exe for a tray icon, that works fine independently

I call it using a windows service, and it seems to run(in task manager) but it dosnt seem to exec any code. ie no tray icon etc.

Answer 1

On Vista and Windows 2008, services run in a different session than the user -- any EXE that a service runs will run in the same session as the service. Before Vista, you need to check the "Allow Service to interact with desktop" box, otherwise the same thing applies.

This means that your tray icon EXE isn't able to interact with the user's desktop. You need to look at using CreateProcessAsUser to run the EXE in the correct session.

This blog post is aimed at people using ConfigMgr OS Deployment, but it contains a good list of the steps needed to run a process in another session. There are some non-obvious steps that you need to take or things fail in weird ways.