Can I upgrade a steam demo to full version?

Solution 1:

I played the demo on Steam (4gb download) and then purchased the game on Steam (another 4gb download). It seems silly but this is the way they have it set up.

Solution 2:

If a Steam demo shares files with the full game, you will have both the demo and the full game in your store page; the latter will be marked as preloaded and doubleclicking on it brings you to the purchase link. When you actually complete the purchase, only additional full-game-only files are downloaded.

If that is not the case, you may have to redownload the whole shebang.

Solution 3:

From the official steamworks FAQ on 2k's Civ V forums:

Q. How will Steam know that I bought a boxed copy of the game?

A. The box contains a product code that you use to register your purchase to your Steam account. The box also contains a disc that contains the data files for the entire game. When you install from this disc, it will install Steam if necessary and then place all of the game files on to your hard drive, negating the need to download the game from the Internet.

So even though you don't have a DVD drive, you shouldn't have a problem installing Civ V, as as soon as you register via steam, you can simply download the game through steam.

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