I installed fallout 3 a few days ago and when I first opened it, it worked until the screen where you can choose new game/load etc. and I chose load but after it loaded for a second, it crashed showing the message 'fallout3 has stopped working'.
After trying loads of things I deleted it and installed it again, and I used the trick with editing the .INI file and using the .dll file. This because I have an intel HD graphics card. And it worked. But then I tried starting it up later and it didn't work again. I did the same as before and it worked.. The game worked for about 5 times of starting up and then it suddenly crashed again (at the beginning, after I pressed play in the launcher) and I didn't manage getting it to work since then. I get that the issue lies with my graphics card, but I wonder why it sometimes stops working and starts working again.

Does anyone have any more ideas about what I can try?

Short of getting a desktop computer with a proper video card, there's nothing more you can do. That video chip just isn't capable of running the game. You shouldn't even be using that dll hack as it's possible to cause damage to your system while using it. You're forcing your video chip to do something it wasn't designed to do, which is why sometimes it works and sometimes it doesn't

sigh.. that's what I thought.. well, good thing I need a new computer anyway.. but a laptop with a good video card (like nvidia) is good to use as well right?