I'm running Windows XP on a Dell Netbook. I installed FO2, and it ran fine. I then put in Killaps' unofficial patch and restoration mod, and began getting the "Fallout appears to be running in compatibility mode" error.

The problem is, I've tried the "check compatibility mode, close, then uncheck compatibility mode" fix, and it still doesn't work... still get the "Running in Compatibility Mode" error, even though I've played with different permutations (click apply instead of ok, different compatibility modes, etc.). I've also tried reinstalling the core Sfall dll, but that also did not work.

I'm trying it, but it's not working so far.

EDIT: Fiddled about with it a bit more. Including the compatibility modes of 256color, 640*480, disable themes and Win98, with it DISABLED or ENABLED, I get "Error Initializing Video Mode 640*480"

This helped. I solved my other problem by fiddling with the settings in the ddraw. Now to figure out how to solve the massive slowness.

Glad it helped a bit. As for the slow downs - that can be a little more annoying to track down. I have run into slow down issues w/ Sacred Gold and the fallout titles. With Fallout I think you have to fiddle with the ddraw settings. Are you using sfall by any chance? That solved many of my slow down issues for Fallout 1 - I don't know if there is an sfall equivalent for Fallout 2 or not though. It has something to do with the rendering engine used by the game I believe - but I am far from the smartest person on this topic and could be far off base.