I installed Fallout last night on my XP laptop, Toshiba Satellite M105-s3041, and an error comes up saying that a 640x480 resolution cannot be accessed or something like that. I checked the display settings and I don't have a smaller resolution or 640x480. I really hope I didn't waste money. I'm also sorry if this question has already been answered, if so please tell me what I can do. Couldn't find an existing thread for this error on XP. - Cheers, SouthEast.

get sfall or resolution mod:
http://falloutmods.wikia.com/wiki/Sfall
read more here as well
you can run game afterwards in window mode, change resolution or display type (directx, etc)

For everyone who may still be having trouble with color problems or display problems with black screens, etc., check out this link. Randomnly found it in a topic on gamefaqs and it helped fix any display issues for me. If it doesn't work the first time then restart your computer and try again, it worked for me when the tool randomnly didn't work sometimes (probably just my computer). Hope this helps.
http://blog.macuyiko.com/2009/07/solving-color-problem-red-grass-purple.html