Originally Posted by Foodchain

I was trying to do this with a memory editor like Cheat Engine but not having any luck finding the memory value for this prompt.


AFAIK Cheat Engine can only modify the heap of the process, not the native code in the .exe itself.
The replaced value is an assembly instruction, "MOVZX EAX, DIL".

Originally Posted by Foodchain

For my own education, how did you find the memory location for that error?


I disassembled the .exe and searched for references to this particular message and followed the call chain to where it'd be the most convenient to stop this check from failing.
Here is what the offending code looks like: https://dl.dropboxusercontent.com/u/32263228/dos/gr2/dos_4ply.png