jimnms: I have the disk version and it works just fine with Win7/8. The problem isn't Windows 7/8, the problem is that the game engine is buged when its run on a systems with more than two CPU cores. Quad core CPUs became main stream around the same time as Windows 7 was coming out and people just assumed it was a Win7 compatibility problem, but it can happen on Windows XP too if you have a mult-core CPU with more than two cores.
I originally played it on a dual core CPU with WinXP, then build a new system with a quad core CPU and Windows 7 and it crashed every few minutes on my new system. It's an easy fix though:
Open the fallout.ini file in: My Documents\My Games\Fallout3
Find the line:
bUseThreadedAI=0
Change it to:
bUseThreadedAI=1
Add another line after it and insert:
iNumHWThreads=2
This will limit the game to 2 cores and prevent the engine bug from causing the game to freeze.
I ran it on my XP Laptop (8 years old and still going) that while still pitifully slow had two cores (pointless because the cpu speed is slow as fuck, so another core did nothing except fuck with my older games) and it ran surprisingly good. Though a game bug fucked me pretty good. The basement Deathclaw fight crashed constantly.
