How do you launch the game in higher res?

[fo3]

Hi everyone, I used to play this game on my ancient PC about 10 years ago. It had lower res so I had no problems (some sktA 3200 with 9600 radeon.)


About 2-3 years ago I tried to revisit this game with a more modern old PC (still 10 year old 1090T with 5770 GPU, just old retired work PCs is how I game) and couldn't get it to launch. Was a shame because I had so many mods and downloaded add ons I wanted to get back to, but I gave up.
Revisiting the games now because I found out it didn't launch on this other PC because it can't launch at res above 1024x768 and it's native res was much higher

Anyway - I have heaps of mods (ARB, GWX, JSGME, supposed res fixers etc), I can PLAY it at higher res but I can't LAUNCH it at native desktop 1920x1080.

Every time I want to play I have to drop my desktop res to 1024x768 just to launch it, then the mods come into play to make it high res just fine.
How come I can't launch it without messing up my desktop and dropping res manually before starting the game? Is there a fix?

I play mostly old games on my old retired PCs and even red alert will launch and drop res to 640x480, why can't I get a modded SH3 to even launch at my native res without "Can not initialize 3d engine" error?
What am I missing? Any hand holding help available here? I've tried so hard and searched and it's all talk about playing at high res (not a problem) but no one has talked about LAUNCHING the game.