I read a good article on Troubleshooting MS-DOS-Based Programs in Windows (Q314106) at Microsoft knowledgebase website. One of the first thing to test when you are having problems with MS-DOS-based programs is the Windows Virtual DOS Machine (NTVDM) subsystem. Open START-RUN and enter command.com or cmd.exe. If you don't see a MSDOS windows coming up you of course have a problem. Check the Config.nt and Autoexec.nt files in the SystemRoot%\\System32 folder for nonstandard settings. Use a REM statement to remark out all entries except the following default entries:
Config.nt
dos=high, umb
device=%SystemRoot%\\System32\\Himem.sys
files=20
Autoexec.nt
lh %SystemRoot%\\System32\\Mscdexnt.exe
lh %SystemRoot%\\System32\\Redir
lh %SystemRoot%\\System32\\Dosx
lh %SystemRoot%\\System32\\Nw16 (only if CSNW is installed)
lh %SystemRoot%\\System32\\Vwipxspx (only if CSNW is installed)
The registry entries that are associated with the NTVDM subsystem are:
HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\Control\\Session Manager\\Environment
This key stores the environment variables from the Config.sys and Autoexec.bat files for use in
Windows.
HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\Control\\ VirtualDeviceDrivers
This key stores the device drivers that are used in an NTVDM session. Windows Setup creates these entries when a device driver is installed.
