ToukoSenpai: I can't choose most of the options in the option tab; I want to change my resolution, for example, yet I can't
And for some reason, the game becomes blurry every time I try to play it; it's annoying.
Game options are saved in a file called GameOptionsSave.xml and graphics options are in GraphicOptionsSave.xml. Both of these files are located by default on Windows in C:\Users\<folder>\Documents\My Games\OldWorld
Not being able to save options suggests that the game is unable to write to these files.
First thing to try would be deleting them both and relaunching the game to recreate them.
If you still can't change settings, check if there is any AV or other software that may be blocking access to these files.
You can also try using a game launch parameter to change the location of the settings files:
In GoG Galaxy, right click Old World and select Manage Installation, Configure, Features and tick the Launch Parameters checkbox.
Click Add another executable / arguments, browse to and select the Old World executable (defaults to C:\Program Files (x86)\GOG Galaxy\Games\Old World)
In the Arguments section, add -userdata C:\OWCustomFolder (or another folder location of your choice)
Tick Default executable and OK