Hello all,
I own GSB and all of the DLC on Steam, but recently got the DRM free version of the base game from the latest Humble Bundle. Is there a way to transfer the DLC from steam to my DRM free version of the game? I prefer DRM free to anything else, and would like to play this on my other desktop and laptops without installing Steam. I love GSB, but not quite enough to rebuy all of the DLC again. And even if I talked myself into it, I’m sure my wife would string me up for buying it twice. 
Thank you.
I don’t have the steam version, but I have moved GSB to another computer. The expansion pack files are on your computer somewhere, and if you can find them you can easily copy them onto a flash drive and put them in your other version.
yes you can just copy the files, you will see them under the games folder in ‘program files’ in a separate folder for each expansion pack. You also need to copy over the contents of the ‘\data\installs’ and ‘\data\packages’ folder to the other PC, for the DLC to register and work ok.
I also own GSB on Steam and got the DRM-free version from the HumbleBundle. So buying the DLC on Steam is a safe way because the DLC will work with both versions or am i wrong? But does it also work the other way around: buying the DLC directly via BMTMicro and adding them to both the Steam- and the HumbleBundle version?
Everything should be entirely interchangeable, as long as you install stuff so it puts the files all in the right place. There is no magic or incompatibility between any of the various versions. If you get stuck, just post your problems in this forum.