Alright, so I bought FS2 a while ago and started playing the campaign, and I've reached a point where it says "Insert CD 3" when I try to continue the campaign, and "Insert CD 2" when I try to play a previously completed mission. What am I supposed to do?

EDIT: Solved, I just reinstalled it.

Interesting.. you should not have that problem with the GOG version of the game. But.. you can try downloading a no CD patch from the net and use that to bypass the cd check. Just google "Freecpace No CD Patch". You can find places to download new FS.exe ( or whatever the freespace executable is called) and replace your existing one with the patched version. be sure to back up your original exe file first in another folder before overwriting, just in case.