I am playing DooM 1 through DooM 3 BFG Edition. I need to confugure the keyboard arrow buttons so they act as "move right/left" instead of "turn right/left".

By default these values are set to

I tried to edit C:\Program Files (x86)\GOG Galaxy\Games\DOOM 3 BFG\base\default.cfg
and modified initial bounded values for arrow buttons from _right / _left to

bind LEFTARROW _moveleft
bind RIGHTARROW _moveright

however it seems that this configuration is probably for DooM 3.

Any idea

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I saw some previous answers to relative questions, however in "Doom 3: BFG Edition" there is no setup.exe file

You're expecting the arrow keys to function as a strafe left/right. This would be something commonly associated with the A and D keys respectively in a modern FPS layout.

That said, Doom 3: BFG edition's in-game settings should apply universally to all games you can play in it - that's including Doom and Doom II, not just Doom 3 and its expansion content.