At work, all desktops use the 64-bit version of Windows 7, but we still have some legacy 16-bit applications.
As XP support is ending, we are using VMWare View to provide 16-bit apps on a virtual 32-bit Windows 7 desktop.
For one of the applications we had this error:
config.nt. The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose 'Close' to terminate the applicate.
Changing compatibility mode made no difference, search results said the autoexec.nt or config.nt is missing, but the files were there.
So I fired up ProcessMonitor and watched NTVDM.EXE which runs 16-bit apps in Windows 7.
WriteFile – C:\Users\Administrator\AppData\Local\Temp\scs1DE8.tmp – Success
CreateFile – C:\USERS\ADMINIST\APPDATA\LOCAL\TEMP\SCS1DE8.TMP – Path Not Found
For some reason, a temporary file is accessed with a truncated username, stopping the app from working.
The work-around was to use a login username that is 8 characters or less, and then it worked.