If you are running an x64 version of Windows then when you try and run an old 16-bit Windows 95 application you will see an error screen saying “This app can’t run on your PC”:

To solve this:

1. Grab a build of winevdm (source) from AppVeyor
2. Extract the artifact somewhere local, open a command window and cd to that directory
3. Run your win16 binary as a parameter to otvdm e.g. otvdm c:\games\game.exe
4. Done!

There’s some background information on why this running 16bit apps doesn’t work, and the virtualisation layers and tooling involved here.

The reason I started looking at this is because I was reminded of an old game called Mordor (here is the official Mordor homepage and here is the demo on the Internet Archive) from some random videogame nostalgia thread somewhere on that internet. Despite the name, it has nothing to do with anything by Tolkien, but is a rogue-like dungeon-exploring RPG.

I had forgotten it existed until seeing its name in that context jogged a 25-year-old memory, and now I can play it again!