I'm running XP pro and FO2 crashes back to the desktop before the game fully starts up.
That is to say I get through the black isle logo, and then the b&w 'scientist' still; however, the still then goes 16-colour'ish on me, and *poof* I'm back to the desktop.
Any help would be appreciated...

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