Enable NTVDM Windows: Turning On Legacy DOS Support

NTVDM (NT Virtual DOS Machine) is the compatibility layer that lets 16-bit DOS and Windows applications run on 32-bit Windows — it’s disabled by default on many current Windows builds, but some older line-of-business or engineering tools still depend on it.

Enabling It

The simplest way is via DISM from an elevated command prompt:

DISM /Online /Enable-Feature /FeatureName:NTVDM /All

Deploying at Scale

For a fleet of machines via Group Policy or SCCM, package the same DISM command as a Run Command Line task sequence step, or a startup script/scheduled task pushed via Group Policy. Since this changes an optional Windows feature rather than installing an application, it’s a lightweight, quick deployment either way.

Important Caveat

NTVDM is only available on 32-bit Windows — it doesn’t exist at all on 64-bit Windows, since 64-bit Windows dropped 16-bit application support entirely. If you’re deploying to 64-bit machines and need to run genuinely old 16-bit software, you’d need a different approach (a virtual machine running an older 32-bit OS, or DOSBox-style emulation) rather than NTVDM.

A Reality Check for 2026

Worth being direct about how narrow this scenario has become: Microsoft stopped supplying 32-bit builds of Windows 10 to OEMs starting with the May 2020 Update, and Windows 11 has never shipped a 32-bit edition at all — it requires a 64-bit processor outright. Combined with Windows 10 itself reaching end of support on 14 October 2025, a machine you’d actually run this DISM command on today is almost certainly an aging, out-of-production 32-bit Windows 10 install predating that 2020 cutoff, running unsupported and unpatched unless it’s covered by ESU. The feature itself still works exactly as described above on those surviving 32-bit builds, but it’s worth treating this as a legacy/retro-computing fix rather than something you’d deploy to a current fleet — if you’re supporting genuinely old 16-bit software on modern 64-bit hardware, a VM running an older 32-bit OS or DOSBox-style emulation (as already noted above) is the realistic path forward.