I have written a Windows Service that runs without any problems on my test pc and on my development pc, but when I install on the pc's that it is developed for a thread in the service is never started. This thread is very simpel and runs perfectly on test and development pc's. Furthermore the service keeps running and all other threads and parts of the code keep working except for this one thread.
The code has been tested with Unit Tests, I have even tryed to run and debug the service as a program. When run as a program on all pc's (that includes the pc that it is developed for), there are no problems. And there are no exceptions that aren't handled.

My own conclusion was that there might be something wrong with Windows, except that it is the same version of Windows that my test and development pc's are running, and I have tryed to reinstall with no succes.

Is there anyone who can tell me what could be wrong

you might add some debug code in that thread that writes stuff to a file so that you can see where it might be failing. Of course this does no good if the thread doesn't start at all.