The echo statements contain a few unintended characters (due to GOG forum settings the repeated ÍÍÍÍÍÍ after a time break up, but you can see the original code in a reply), but other than that the code matches my own.

What I'm guessing is the problem is that my folder structure may not be the same as GOG's folder structure. I have a tendency to make GOG's DOSBox games into portable applications, so I separate the game files from DOSBox and run them via my own batch file that references the relative path to the DOSBox executable. If this is the case then when you run my autoexec script it won't find the files and will error, therefore hitting the exit lines and quitting DOSBox.

To explain my folder structure, my .conf file mounts the C drive for the game as mount c ..\POP as the game files are all in the folder POP which is alongside the DOSBox folder. You'll likely have to modify the mount commands to the relevant paths for your GOG installation, but the rest of the code runs fine. I've attached some screenshots showing my folder structure.

Hmmm, i'll try some experimenting and see what happens...

Okay, it seems Windows Explorer really doesn't like that as using that setup has caused Windows Explorer to crash for a second time. I think i'd better just wait for gog to do their own fix for this as I don't want to risk screwing something up real bad. I appreciate you trying to help anyways though.

Windows Explorer crash? From some simple copy and replace commands and then launching the game in DOSBox? I highly doubt the script is doing that. Even if Explorer cannot find the file in question it just throws an error message or does nothing. There is nothing in my script that GOG and DOSBox haven't used before (that's where I learned how to do it after all).

Just noticed something. Where is the rest of your conf file? I only posted the [autoexec] section. You still have to have the rest of the DOSBox conf file somewhere (either in the same .conf before the [autoexec] or in a separate conf file called in addition to this one.

The other settings (aspect ratio, cpu cycles, etc.) are in a separate main config file. I was replacing the the text in the separate autoexec file that gog made, should I add your autoexec to the main config?
Yeah, that's what baffles me too, it shouldn't be doing that.

Edit: (see attached file) I'm using the default gog install path and basically what i'm doing is replacing the text in dosboxPOPULOUS_single. I assume the problem is that our installs are set up differently and I have to figure out what to modify the command lines in autoexec to get it working with mine.

Okay, that's fine. I do in fact use two .conf files myself, as that is how they extracted from the GOG installer:

The first one, dosboxPOPULOUS.conf, I didn't change at all, so leave that one as it is.

The second one, dosboxPOPULOUS_single.conf, I did change to my new autoexec script. The other two are for setting up client and server for multiplayer, so I don't make use of those, but the GOG setup can do and they can have the same lines of batch script for choosing the graphics set, should you want to.

To try to help you, I've changed my mount command to that used by the GOG installation and attached the dosboxPOPULOUS_single.conf file here. You'll have to right-click and save the attachment to your PC then rename it to dosboxPOPULOUS_single.conf, making sure that you lose the .jpg file extension (a .jpg extension was the only way I could get it uploaded on GOG forums). I recommend that you display file extensions in Windows Explorer as I noticed from your screenshot that your current setup hides known extensions.

Oh, and make sure that you've made copies of the relevant data files. In the DATA folder, make a copy of LEVEL0.DAT named LEVEL_OR.DAT, and make a copy of LEVEL1.DAT named LEVEL_PL.DAT.

As I said, I cannot upload a .conf file here as GOG forums only support image files. So I renamed the file extension to upload it.

Right-click it, save file as, and once you have it saved on your computer rename it so that the .jpg file extension is removed. The file is actually just a plain text .conf file. Rename it to dosboxPOPULOUS_single.conf.

Ah, forgot about having to rename back to conf to get the text to show. Now to test it.

Yep, it works! Original and Promised Lands work perfectly and with no crashes this time.

Thank you so much uploading that redone text file and for putting up with my odd self, lol.

Great news, glad it worked.
Still no idea why you were getting Explorer crashes the first time. The only change was the mount command, after all.
Anyway, enjoy! :)