Find and check NTVDM (NT Virtual DOS Machine). Note: This is rarely available on modern 64-bit systems. Use Compatibility Mode: Right-click the program > Properties > Compatibility .
16-bit applications use segmented memory addressing and rely on the subsystem. In 32-bit Windows XP/Vista/7, WoW allowed 16-bit binaries to run via a thunking layer. unsupported 16-bit application
Compatibility Mode for Unsupported 16-bit Applications Find and check NTVDM (NT Virtual DOS Machine)