I'm Jason Firth.
Industrial systems are unbelievably static compared to other systems. While the rest of the world struggles upgrading to Windows 10 from Windows 7, some industrial process control systems are still on Windows XP. In fact, there are even some still plugging away on Windows 98. These devices often aren't treated as computers, but as appliances.
This happens more than you think. Many internet connected devices out there today run Linux as a bottom layer, and there isn't even a mechanism to get into the device, let alone upgrade it.
For front-line technicians, this can be a bother. There are twin concerns: On one hand, you want to have the latest OS for the latest software, but on the other hand you have issues leaving behind old software.
Recently, Windows 64-bit OSes have become standard. Microsoft finally decided, after 25 years of supporting it, to drop Windows 16-bit and MS-DOS support. This makes sense for them from a business standpoint, but makes things complicated where you want to run that software.
Windows has maintained support for old OSes long after their end. Windows 3.1 applications functioned properly under Windows 95,98,ME,NT4,2000,XP, and 7 32-bit. They function by running a special program that allows the 16-bit applications to run on 32-bit OSes. In the 64-bit OSes, they have removed that functionality.
This causes a problem for us when software that won't get any updates but is mandatory for your operation is a win16 program. Instrument configuration programs, old PLC programming software, cross-reference software, and more might be stuck on win16, putting you in a bad position.
I found a piece of software called winvdm that appears to solve this issue. To install it, you download the software, place it onto some folder, modify the included registry file to point to the folder you've created, and run the registry file. After that, windows 16-bit programs will open natively with no additonal work.
Thanks for reading!