In Windows NT, each application written for MS-DOS runs in its own NTVDM process.
Windows NT runs the application by using a NTVDM and VDDs. This process is called WOW, for Win16-on-Win32. Using a 16-bit NTVDM, Windows NT translates Windows 3.1–based application calls in Enhanced mode on all Intel-based and RISC-based computers.
Control parameters for WOW startup and for the WOW application environment are found under the following Registry path:
HKEY_LOCAL_MACHINE\System
\CurrentControlSet
\Control
\WOW
The system maintains the settings in this key automatically. They should not require manual changes.
The environment settings equivalent to the System.ini file for Windows 3.x are found in this Registry path:
HKEY_LOCAL_MACHINE\Software
\Microsoft
\Windows NT
\CurrentVersion
\WOW
The WOW subkeys have the same names as headings in the System.ini file, and the values are the same as items contained in the old System.ini file. For details about these entries, see the online Help for the Registry.