There seems to be no easy way to reconfigure the sound setup for the game. I'm trying to set it up to use the gravis ultrasound emulation in dos box I was able to run the setup program by manually mounting the iso and game directories. the setup detects the gravis card, but when i try to save the settings (I get an error about being unable to save setup.bat. This is quite frustrating as i want to play the game with better music options. Is there anyway around this problem?

Thanks

First, I recommend disabling cloud sync, because otherwise the GOG tooling will try to put changes in the cloud_saves folder and tell their special DOSBox build to overlay that over the rest of the game files.

After that, open TN\SETUP.BAT in Notepad or whatever, and change the "targ_dir:c:\tnova" part to "targ_dir:c:\tn". Open TN\TN.CFG and similarly replace all instances of "c:\tnova" with "c:\tn". Save and close the files.

This should make the setup program work. The safest thing to do is edit dosboxTerraNova_single.conf and add the following like just before the ff.bat line, then launch the game using GOG Galaxy or a GOG-created shortcut:

call setup.bat

This will cause the setup to run every time just prior to the game itself.