Depending on whether you play the DVD or the CD version, and whether you only want to play multiplayer, or also the single player, you either only need the DVD, only the CDs 1 and 2 or all CDs. To install you need CD 1 or DVD. To play the multiplayer you need CD 2, for the singleplayer you also need the other CDs, because they contain the ingame cinematics. On the DVD everything is included anyway, so it doesn't matter here. It is recommended to install the KA-Patch 1.02 afterwards (unpack the contents of the archive into the game directory) and for Windows Vista and newer the Komats Patch as well (also unpack into the game directory and start the
kalaunch_patcher.exe. Then use the
KALaunch.exe to play). You can also set the screen resolution.