QUOTE(Renee @ Jul 26 2024, 06:33 PM) 
Don't worry, I already fixed my (latest) prob. I'm just posting my fix for anyone else out there.
Was reinstalling Fallout 3 from GoG and was going crazy, because the black-screen-on-launch happened.
Tried a .dll fix. Tried to set FO3 executable as Administrator. Tried setting Compatibility Mode. Each of these 'fixes', I had to get up from my comfy chair over and over because the game would blackscreen, and then I'd have to get up from my chair to turn off/restart my computer.
No mods or utilities installed at all, yet! -- However, at some point I discovered I could run the game in Windowed mode. HMm. Was about to install the Anniversary Patcher when I just happened to notice that the Full Screen setting in the launcher was set at some resolution I don't use. Ah-ha! It should be 1360 x 768. Bang!! Now the game starts & runs. Phew.
It's just a reminder to myself and others: always check the small, easily-overlooked stuff too.
Glad you were able to fix it and return to your adventures in the Capital Wasteland!
I think the difference this time is I used an older version of FO3Edit to clean: Version 3.1.2 this time. I'd been using 4_0 in the past, which for whatever reason wasn't getting the job done, so I've been playing dirty all these years. Anyway, in the past my habit while gaming has been to save/exit/reload the game every 20 minutes or so, which was my way of avoiding the sure-to-come CTD. Now my habit's going to change to gaming as long as I can, just to see if a CTD occurs.