I have a CD copy of Napoleon: Total War, and installed it from disc. Now when I try to play, Steam starts trying to download files for it, 5 GB's worth. I'm on mobile broadband so I can't afford this. I have uninstalled Steam / Total War and then tried re-installing both, but still the same problem occurs. Any solutions?
You could tell Steam to not update games automatically, by right clicking on the game in your library and then clicking on
Properties > Updates and choosing
Do not automatically update this game
If for some reason, Steam still believes it needs to download something, you will possibly need to find a wireless or wired network other than the mobile one to download the remaining game data.
Your best bet might be asking a friend who has it also installed for the file
appmanifest_34030.acf (in Steam's subfolder steamapps, at least if 34030 is the correct ID of the game) and hope this is enough to make Steam believe it already has the game data. You may however still end up downloading some updates, whether you like it or not. Or your friend uses Steam's backup function and sends you two DVDs...