Trying to view Print SCreen images

I have a game called Starcraft (by blizzard). When playing tourney games, i have to make Screen Shots of winning screen to ensure they give me my win. Now, they SS’s save into my starcraft directory. They save as ext. PCX in bitmap form. Normally, im able to just open them up and they will open with paintbrush. However, whenever i try to open one now, it says “Invalid bitmap format”. This is right after a clean install of windows. I tried to reinstall paint but that doesnt work. I reset the default bmp size in paint. Nogo there either. Anyone have ideas? (note, i know other 3rd party programs will work, but id like paintbrush to work, therefore, that other programs is not a valid answer). Thanx!