which program to do pixel editing?

[TLF]

I tried Paint in WinXP and Civ didn't like the resulting file.
I guess Paint saves gifs in a way that Civ doesn't like. All I did was changed the colors of some pixels.

I'd like a simple, small, free program.

I know about (and have used in the past) Gimp, but it is way more than I need.

 

[Arthedain]

I've always used paint without a problem. The trick is to copy an existing working .bmp or .gif and then edit that one. Come to think of it, I've experienced some problems with .gif's but not with .bmp's.

I know that many use paintshop pro 8 but I don't think it's free.