I downloaded Alliance of Valiant Arms some while ago.. before installing windows 7 I just copied the ava folder into a temporary partition. Now I am trying a direct copy and paste from that partition to steam/steamapps.. except that isn't working. Can I get i working without downloading AVA all over again? I want to download Planetside 2 from steam.. but if I have to download again whenever I change OS or computers it's going to be a PITA and not worth going over the bandwidth limit. Any ideas?
It looks like you may have forgotten the cache file. Steam needs those to know what files are required for each game.
I have done this on my own computer while I was upgrading my OS. There is no need for any special backup feature or middleman program or function.
I did exactly as above to the entire contents of the SteamApps folder when I upgraded my computer, and everything worked flawlessly.