I have recently installed War Chest on my new laptop with Windows 8.
Allied Assault goes without any problems (completed Easy difficulty so far) but when I try Spearhead and Breakthrough, games crash. And changing compatibilities to even Windows 98 do not work at all.

What happened? Why Allied Assault works fine. but it's expansions don't? Is it some kind of glitch for GOG version on Windows 8? What do to, in order to play these games?

Same goes for me. I would really love to play this again but unfortunately it does not run on my Windows 8 PC.