Installing NTVDMx64

This method has been tested but is not supported by the ProBoard authors or test team.

Information: http://www.columbia.edu/~em36/ntvdmx64.html

Only 32-bit editions of Windows include the “NT Virtual DOS Machine” known as NTVDM, which allows DOS applications to run in emulation mode. Microsoft did not include NTVDM in their 64-bit editions of Windows.

NTVDMx64 is a patched version of Microsoft's NTVDM, for 64-bit Windows. It is based on leaked Windows 2000 source code, which was updated by the OpenNT Project and includes modern build tools. A programmer known as Leacher1337 has ported it to support 64-bit Windows by creating code-injection loaders that convert the 32-bit and 64-bit structures back and forth without altering the protected Windows system files.

NTVDMx64 an open-source project on Github: https://github.com/leecher1337/ntvdmx64

The full binaries and installer can be downloaded from the University of Columbia here: http://www.columbia.edu/~em36/ntvdmx64.html The current version is dated April 12, 2021

Before installing NTVDMx64 on Windows 10, it is important to disable Windows Defender “SmartScreen” and if you use Microsoft Edge to download it, you will also need to disable “SmartScreen for Microsoft Edge”. These can both be disabled by clicking on: * Settings> Update and Security> Windows Security> App & Browser Control

Antivirus software should also be disabled during the installation, and if your Computer's BIOS has an option called “Secure Boot” then this must also be disabled in order for NTVDMx64 to function. If “Secure Boot” is detected, the installer will open a Microsoft web page that explains how to disable it.

To install NTVDMx64, first extract the desired language folder from the .7-zip Archive into a folder on your computer such as c:\NTVDMX64 and right-click on the install.bat file and select “Run as Administrator”. The installer will ask if you wish to install support for 16-bit Windows applications (WOW32), which you can answer “No” to and it will just install support for DOS applications.

If you encounter issues installing NTVDMx64, you can open a support ticket on the Github page. A recent sysop encountered install issues and was assisted here: https://github.com/leecher1337/ntvdmx64/issues/101 Since then, this issue was resolved in the October 4, 2020 release of NTVDMx64.

You can optionally install the HAXM edition of NTVDMX64, which supports Intel Virtualization Technology (VT-x) hardware acceleration so it is scientifically faster in textmode. HAXM requires a modern (2017 or later) Intel CPU with VT-x. To determine if your CPU supports Intel Virtualization Technology, visit https://ark.intel.com and select Processors > Find Processors by feature, or download the Intel Processor Identification Utility. Using HAXM, NTDVMx64 will run textmode applications nearly as fast as Microsoft's original NTVDM for 32-bit Windows editions.

Note that when using the HAXM edition of NTVDMx64, the WOW32 feature can not be used, WOW32 allows support for 16-bit Windows applications made for Windows 3.1 and earlier. If such support is desired, there is a much better solution is available here: https://github.com/otya128/winevdm