Definitions for "VDM"
Windows: Virtual DOS Machine
virtual DOS machine. A Windows NT protected subsystem that supplies a complete environment for MS-DOS and a console in which to run applications for MS-DOS or 16-bit Windows. A VDM is a Win32 application that establishes a complete virtual x86 (that is, 80386 or higher) computer running MS-DOS. Any number of VDMs can run simultaneously.