Which version of DOSBox?
How have you mounted the drives in DOSBox?
How did you install it?
How do you start it?
What kind of mouse do you have?

Which version of DOSBox? DOSBox 0.65
How have you mounted the drives in DOSBox? Drives were mounted as per the instructions in the README. I assigned virtual C drive to the real folder D:\Games\HeroQ and virtual D drive to my CDROM drive which is real drive E:\
How did you install it? I installed by the installer that came with the game. Autorun, setup.exe. When that gave me no initial results, I tried uninstalling, mounting the drives, and running setup.exe through DOSBox and received the message "This cannot be run through DOS"
How do you start it? I started the program each and every time through the Windows Start menu.
What kind of mouse do you have? Mouse is a Keio optical scroll mouse that is quite aged and probably needs replacing anyway. It has worked unfailingly all this time and has shown no other problems with any other kind of program up until now. Its only problem seems to be that it's getting so old that the scroll wheel tends to stick when I try to scroll up, not a software problem but a hardware problem. (I'm asking Santa for a new mouse. 😁 )

DOSBox 0.65

Why?

Is this Hero Quest or Hero's Quest?

Why not? It came packaged with the game.

And, yes, it's Hero Quest, the video game based off the board game. Not Hero's Quest.

Why not?

Because 0.65 is ancient.

Oh and you downloaded the game somewhere? Is it freeware?

It is usually a bad idea to install something from Windows, and then run it through DOSBox. If you do, it is advisable to keep the directory names in the old 8+3 character format, and to mount the DOSBox drives so they match the physical drives (C => C:\ and E => E:\).

I am pretty sure you don't start the game through the Start => Programs menu. Maybe you start DOSBox that way, but that shouldn't start the game.

It is usually a bad idea to install something from Windows, and then run it through DOSBox. If you do, it is advisable to keep the directory names in the old 8+3 character format, and to mount the DOSBox drives so they match the physical drives (C => C:\ and E => E:\).

I believe the filename length thing I tried to keep in mind, especially when creating the folder in which to install the game. As for the naming of mounted drives, I was told otherwise on the DOSBox wiki. Said to keep the naming of the virutal drives to C and D.

I am pretty sure you don't start the game through the Start => Programs menu. Maybe you start DOSBox that way, but that shouldn't start the game

Alright, but seeing how it managed to start the game in the first place using this technique... Might you suggest instead how I COULD start the game?

I would expect something like this:

1. Start => Programs => DOSBox-0.72 => dosbox.exe
2. Z:\>mount C C:\
3. Z:\>mount E E:\
4. Z:\>C:
5. C:\>cd hero
6. C:\>hero.bat