>We have a customer who is trying to install our app on Windows XP 64 bit edition and is getting a message from Installshield Express (that came with VFP) saying "The operating system is not adequate for running {our product name}". I'm not sure why it's saying this, and since we don't have any 64 bit machines I don't have any way to experiement with it to figure out the issue so I can fix it. How can this be dealt with or fixed? BTW, we have the install setup to refuse installation on Windows 95 or NT. I'm wondering since it looks like in that case it's checking for specific OS versions if that means that restricting older OS versions also means restricting newer ones that the installer didn't know about when this version came out?

Be sure that in InstallShield Project you checked that your application can be installed on All Windows OS.
I think this is a issue of IS. I have similar problem becuase I unmark Windows95 in IS project and application doeasn't want to be installed on Windows 2003 :-)