Old Games and "The NTVDM CPU illegal instruction."

[Syrinth]

Hey, I'm trying to play some old games *The Quest for Glory series by Sierra* and I keep getting the following error:

16 bit MS-DOS Subsystem
<path name to the file I'm trying to use>
The NTVDM CPU has encountered an illegal instruction.
CS:c000 IP:00ac OP:ff ff ff ff ff Choose 'Close' to terminate the application.

[close] [ignore]

I used to be able to play these games on windows XP before but I recently built a new computer and have all new pieces. I've checked several other pages involving the NTVDM issue and have done my best to do what I can but whenever I try to open the games I get that problem.

I've replaced the NTVDM.exe file with a new version of it to make sure that it was corrupted and am now confused. Yes I am aware that I can use DosBox but I really, really don't want to if that's at all possible.

Lastly, I tried doing the SFCSCAN but I don't actually have the CD used to install my OS *mine was not working apparently so I used the computer shop's*

Any help would be GREATLY appreciated.

 

[Syrinth]

*bump*

 

[N3051M]

try right clicking the .exe files and go to the compatibility tab and set it to windows 98 or 95..

 

[Syrinth]

nope, it doesn't work sadly.

 

[Nodsu]

Do you happen to have 64-bit Windows XP on your computer? If yes, then maybe that's your problem?

If you don't like DOSBox, then maybe use VMWare? It's free for personal use

 

[Syrinth]

What do you mean 64-bit windows xp?

 

[Nodsu]

It is the version of Windows XP professional optimised for the new 64-bit PC processors made by AMD and Intel. Officially called "Windows XP Professional x64 Edition"

 

[Syrinth]

ah, well no I don't have that lol

 

[andwan0]

I used to get that exact same message with the exact same address/hex values.

It's because of your new 64-bit CPU.

NTVDM.exe allows 16-bit DOS programs to bypass the 32-bit Windows OS ... passing their 16-bit instructions directly to the CPU. Only 32-bit CPUs can understand 16-bit instructions (aswell as 32-bit instructions. But 64-bit CPUs can only understand 64-bit & 32-bit instructions...

Using VMware won't help because VMware too transfers the DOS 16-bit instructions to your physical CPU because of NTVDM.EXE.... and if your CPU is of 64-bit nature then it'll throw up 16-bit instructions....