When Valve launched SteamOS, it was definitely a beta product. Its installer prompted Ryan to make a troubleshooting video on our Youtube channel. It also apparently required a computer equipped with a UEFI which only became common about two or three years ago. It is also very difficult to install as a dual-boot configuration which complicates its coexistence with Windows (because Microsoft will certainly not support it from their end).
Thankfully, most or all of these issues are being addressed in the latest beta SteamOS ISO… at your own risk. They are very careful to highlight that this beta has not been properly tested. Given that their initial release could nuke a random hard drive full of data, I would take that warning seriously.
These changes come from the project, "Ye Old SteamOSe". I am not sure that it solves the USB overwrite issue that we experienced (unless it was already fixed at some point) but I would expect that custom partitions and dual-boot would be impossible if that bug still existed. The highlighted features, according to the announcement's comments, are:
- Non-EFI support
- DVD install support
- Custom partitions in Expert mode (cannot resize NTFS partitions).
- Dual-boot in Expert mode.
If you would like to give SteamOS installation another shot, on a machine that you feel comfortable testing software with, then check out the Steam Universe thread.