Domochevsky: I know this has already been solved, but you can also go into the registry and set the following key...
HKEY_CURRENT_USER\Software\Triumph Studios\Age of Wonders\General -> Language = 1
That would set the game to purely english. (I had the same issue with half the game being in german.)
Well, that doesn't work for me.
I updated that key to Language 1 in hexadecimal, then I re-ran AoWSetup.exe and keeps showing the local language, which causes the AoWSetup.exe to send an access violation. I will try re-installing.
Update: I re-installed and uninstalled several times. There seems to be a bug on AoWSetup.exe. Basically, I need to uninstall, and delete the complete registry (regedit) key and then do a clean install. And then, after installing, I need to click on "launch game" button right out of the installer, so AoWSetup.exe is forced to run. Here, I need to make sure to never touch the "Language" option. Here I just need to update the resolution and click save. Then either launch the game or exit. But after that, AoWSetup.exe never needs to be run again, or else it will force the local language in the configurations and screw everything up. If I want to update the resolution, i need to do it in the registry, as I cannot go back to AoWSetup.exe.
For launching the game, I just run the direct access in the desktop.
Anyway, thanks for your input, as this 1) told me where the registry key was and 2) brought a whole idea of updating the resolution via registry, instead of AoWSetup.exe, so your help was helpful and I appreciate that.