Now that you know why the program cannot access the file, it is time to figure out which process has already put a lock on them. The error could appear in any program ...

It was my understanding that I would have to add a file system watcher for each of those directories, versus my current system where I can just add another entry in a database and the next time around ...

* I am aware of the various task libraries out there. For internal reasons, I need my own task, even if already out there. I've written a simple custom msbuild task to concatenate some text files to ...