Thanks for the suggestion, but I don't think that will work, for two
reasons:

They could be running it on a client machine, pointed at a shared
destination on a folder. The MUTEX would catch that.

If an earlier installation died part way through, I want to know that
it was underway and unfinished, so that the support staff can ensure
that it's OK.

That's why I was leaning toward using creating a file called
"Installing!" in the destination folder. If the file existed, then
they could not proceed with a subsequent installation. That file
would be deleted near the end of the install script (after everything
has safely completed).

Mike Hanson
www.boxsoft.net