FoxPro 2.6 DOS on Windows 7 64-bit

It looks like you don't have many viable choices.

The easiest and fastest is b option using XP Mode. XP Mode, as a virtualization option, integrates the installed application in XP, in Windows 7.

Give it a try.

My guess for the reason that it doesn't run and will not run is because it's actually a 16-bit application. Apparently, Win64 doesn't include the WoW Win16-support subsystem required to run 16-bit apps.

You can definately run 32-bit apps on 64-bit windows. But if yours is 16-bit then you're going to have to run an emulator.

If it really is 32-bit then make sure the 32-bit libraries are installed and available. Also make sure to disable Data Execution Prevention or add your app as an exclusion to it or it also won't run.

All the old 16 bit addressing compatibility modes were left out of 64 bit mode when AMD developed their 64 bit extensions to the x86 processor. This makes it impossible for Windows on Windows 64 bit (WOW64) to support running older 16 bit software in the same way WOW32 is able to on a processor in 32 bit mode.

The 32 bit versions of Windows 7, 8, 8.1 and 10 all still support 16 bit software - you just need to enable the legacy feature NTVDM (NT Virtual Dos Machine) and can even type command at a NT command prompt to switch to a DOS command line.

I would suggest running it in a virtual machine using a 32 bit version of the main OS the company is currently running - so Windows 7 32 bit for now.