>When I select Tools...Options, the dialog box that comes up allows me to change only two things: Project Location and Help Window On Top; there is no File Location tab. ISX help confirms this and has no reference to the File Location tab. Remember, I'm working with ISX VFP LimitedEdition.

OK, I couldn't recall if that feature was available in the limited edition or not. Sergey's advice to read the InstallShield Express Issues section in the readme.htm on the VFP7 installation CD may help you here, although you seem to have the opposite problem. The information in that article pertains to ISX 3.0, but there should be a corresponding key for ISX LE in your registry that will tell you where ISX LE is looking for merge modules.

>Is a reinstall my only good bet? I watched the admin install the package, and there were no questions asked or answered re: file locations.

VFP7 is already installed on your machine, right? The VFP limited edition of ISX is supposed to locate and link to the VFP7 merge modules automatically, so reinstalling ISX LE might be a good idea, especially if you don't want to hack around in the registry manually.