> My setup.py creates a .dll then later loads the dll for testing 
> using ctypes. Subsequent runs of setup.py that would force 
> rebuilding the .dll attempt to delete the old dll first if it 
> exists, but I get permission denied.
>
> Oddly, if I put the load library call inside a function, then, 
> after exiting the interpreter the dll can be deleted.

I'm having trouble imagining what the problem could be here. Can you attach a minimal example script that reproduces the problem?