[Skybird]

^ As I said, this is what I did. And right that does not work. No matter whether I chose the HD as a whole or just a subdirectory I created on it for Steam - it is not "valid" since not empty (while it is empty for sure, I also made sure it is set to read AND write).

And how would a different software, say any non-game, get installed on the other drive? In the case of Steam, the steam launcher nevertheless goes to the SSD, the primary HD, that is.

So far the situation for me is loike with certain Android versions and cellphones: you can move data to the external SC card manually, but it does not let you install an app o it directly.