>>Another type of "virtualization" people talk about is Windows' remapping of certain folders and registry entries in a user's profile. However, files stored on a network share are not subject to this.

>In the case where the program stores its datafiles in its home directory, and the program is installed in "Program Files", I would guess that you'd likely run afoul of weirdness from directory virtualization when you run the program directly on the host computer. Likewise, in the case where you're using remote desktop into the host computer, that you're probably going to run into the same situation as running directly at the host computer (since with remote desktop you are in effect running on the host).

That's my understanding. I think it's mainly that by default you can't modify files in "Program Files" so VFP apps start getting "access denied" errors.

>What I'm not sure what will happen is in the case where you set up the program folder in question as a network share. Would the host system enforce directory virtualization in this case? Or would enforcement be subject to configuration of the client? Would there be any difference if you running in a domain or peer-to-peer type environment?
>We've been in general avoiding the issue by instructing the users to *not* to install the program under folder such as "Program Files"

That's an ugly scenario that should never arise in practice (not saying no-one has ever tried it :-/). It's so far away from best practices that I'm not even interested in testing it. Nonetheless if weirdness were to occur I'd expect "access denied" problems rather than different numbers of rows appearing in tables accessed by different users. So I don't know how it could cause what the OP is seeing.

My general principle is anything shared by multiple computers gets a separately defined share on the "server". If program + data are shared, everything should be installed to the share. If just data are shared, the data can go in the share, and individual computers can install the program to their "Program Files" folders. Of course, in the latter case if more than one user/profile is expected to be able to run the program on a given computer, it needs to be installed so it's available to all users.