Hey, I installed Fallout today and... it don't run. I mean clicking on the exec just do nothing, maybe launches and closes fast (checked Windows Task Manager) but... nothing.
I'm on this configuration :
E8400 non o-clock,
ATI X1950 Pro 256 PCIx16
4GB DDR2 5300
Win XP pro SP2 32bits
Halp plz! Thanks

Ok well nevermind I've got this solved. If any of you have the Ati Tray Tools installed and running, exit it to be able to play. That's the fast way, at least (too lazy to tweak one by one every parameters).
Solved o/

It doesn't play nice with Tray Tools? That sucks. I use it too.

it also "hates" nvidia control panel. plus, when you alt-tab to desktop and have nvidia cp open, the game does not alt-tab back.

Thanks for the update. I wouldn't have suspected ATI tray tools.
On a hunch I went into ATI tray tools and disabled the on-screen display of FPS.
Right click on Tray Tools, "tools and options", and disable it.
Fallout booted up right away after I disabled the FPS meter.
Probably a conflict with the overlay and old, old school DirectX.
Hope this helps.