How to run DOS programs in a current version of Windows

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Kenneth M. Frith is moving away from Windows XP (as he should). But he still has some old DOS programs he’s either unwilling or unable to give up. Can they run in Windows 8?

The big question is: Does your new PC run the 32- or 64-bit version of Windows 7 or 8? If you have the 32-bit version (referred to as x86 for historical reasons), you should have no trouble with many (but not all) DOS programs. But if you’re using the 64-bit version (x64), running a DOS program is officially impossible.

But that doesn't mean it can't be done.

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Some DOS programs will not work in any current version of Windows. Generally, these are utilities that work close to the hardware, such as defraggers and diagnostic tools. But really, you shouldn’t be running outdated versions of these tools, anyway.

Some DOS games also run close to the hardware, and these might not work in Windows, either. But these will probably work in a virtual machine. I discuss that option below.

If you don’t know if your PC is running a 32- or 64-bit version of Windows, now is the time to find out. In Windows 7, click Start, right-click Computer, and select Properties. In Windows 8’s Search charm, type pc info, and select PC info. Either way, you’ll find the answer in the System Type field.

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Identifying a 64-bit version of Windiws 8.

If you’re running the 32-bit version, you can launch a DOS program by simply selecting the .com file. The first time you do this in Windows 8, you’ll probably be asked about installing a feature called NTVDM; click Install this feature.

If the program fails to run, or if you’re running Windows 8 x64, try running it in DOSBox. This simple, free program runs DOS in a virtual machine that comes reasonably close to emulating an old-fashioned computer.

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But there’s one tricky part about setting up DOSBox: You need to create a “drive” for it.

First, in Windows Explorer (File Explorer in Windows 8), create a folder as close as possible to the root of a real drive or partition, and give it a short name without spaces or punctuation. I recommend C:\DOSfiles. Put your DOS programs and files in that folder.

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Then, in the Start menu's Search field, or in Windows 8's Search charm, type dosbox and select DOSBox 0.74 Options (the number might change). This will bring up a rather large file in Notepad. Scroll to the bottom. Below the flag [autoexec], type in mount a c:\dosfiles. Save the file.

From then on, when you launch DOSBox, it will see the C:\DOSfiles folder as drive A:.

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