Each MS-DOS-based and 16-bit Windows-based application runs in a Windows NT virtual MS-DOS machine (VDM). Windows NT includes the necessary virtual device drivers (VDDs) for the mouse, keyboard, printer, COM ports, and network support. The VDDs are loaded into every VDM based on values stored in the Registry. Information about VDDs is found in the following registry path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\VirtualDeviceDriversAny changes to the VDD entries are managed automatically by the system when you add a device driver using Windows NT Setup.