Windows-only programs

If a program exits immediately at startup saying:

…or similar, this means that the program is Microsoft Windows-only and cannot run in DOS.

Boxer can only emulate MS-DOS programs, and will usually detect and warn you if you try to start a Windows program or import a Windows-only game.

Alternatives for Windows emulation

Crossover Games is a good alternative for running Windows-only games. It has a similar workflow to Boxer, and allows you to install and play many Windows games without needing a copy of Windows itself.

Another option is a virtualization suite such as Parallels Desktop or VMWare Fusion. These let you install and run Windows within a virtual machine on your Mac, and thus require you to have a copy of Windows.

But I thought this was a DOS game!

Many PC games around the 1995–1997 transitional era were released for both MS-DOS and Windows: sometimes as completely separate products, and sometimes as both versions in a single installation.

If you encounter a Windows program, it’s worth trying other programs in the same folder to see if they work in DOS. Unfortunately, since DOS and Windows programs both use the .exe extension, you can only tell by trying to run them.

Boxer’s game importer weeds out Windows-only installers and will only offer actual DOS installers to choose from. And if the importer says the whole game is Windows-only, that means it really is.