Vista - 16 bit MS-DOS Subsystem error... still can't find answers...

Ok I downloaded a game from a trusted website that I've used many times before I know it's not full of viruses or anything and my computer is virus free as well. But when ever I attempt to start the game this message appears:

16 bit MS-DOS Subsystem
C:\PROGRA~1\EUDEMO~1\AUTOPA~1\update\enmy\1176.exe
The NTVDM CPU has encountered an illegal instruction.
CS:1206 IP:01bf OP:63 72 6f 3c 2f Choose 'Close' to terminate the application.

This does make sense because I've been playing another game from the same makers and have had no problem. I've searched the web and Microsoft's website and even tried a couple things but no one's problem seems to fit my own and the other solutions surely don't work so could someone please please please help me out? I'm using Windows Vista Home Premium 32-bit (which came already installed on this computer.)

Hello theone764,
Take a look here.

Troubleshooting NTVDM and WOW Startup Errors

and here.

The NTDVM CPU has encountered an illegal instruction - Tech Support Forums - TechIMO.com

This is more common than i thought. Good luck and post your results.