I have Vista 32 and Nvidia mgt8700 card
Bought Fallout 1 and 2 from GOG yesterday. Everything was fine. Played 12 hours with both...
Today, can't run either of them, I receive the dreaded : "error initializing 640x480 video mode".
Can't seem to create a custom resolution with the (very non-intuitive) Nvidia control panel...
Tried restoring my system to earlier point and reinstalling the game...Nothing works.
What could be the problem?
Tks

In earlier topics about the issue several people have stated that renaming ddraw.dll in fallout directory solved their problem. You may also download sfall and replace the old ddraw.dll with the one that comes with sfall (it also adds middle mouse scrolling capability and various video mode options for both games and fixes few bugs in FO2. Note that both killap's patch and restoration project come with and utilise earlier version of sfall and removing ddraw.dll in such installation will cause problems).
Alternatively you can try High Resolution Patch available at NMA and edit following lines in "f2_res.ini" to find workable resolution
;Set the screen resolution here
SCR_WIDTH=640
SCR_HEIGHT=480
;Set the number of colours here
; 8 for 8bit(original)
; 16 for 16bit colour (set only if your not using Sfall with graphics modes 4 or 5)
COLOUR_BITS=8

I posted a FAQ which addresses this issue, you should read it.
http://www.gog.com/en/forum/Fallout_Series/fallout_1_faq/_/1