Finally, we can start up our virtual machine and install SteamOS. Frankly, this process is a bit confusing and involves a fair amount of manual tweaking as you go. Follow along with each step, and you shouldn’t have any problems getting into SteamOS.
Double-click on the SteamOS machine’s icon in the left-side column of VirtualBox. A new window will open, which acts as the “monitor” for your virtual PC. After just a few seconds you’ll see the SteamOS installation menu in it. (If you see “Error: Prefix not set,” just wait it out.) Choose the first option, “Automated Install,” using your keyboard. It says it will erase your disk, but don’t worry! That’s only true inside the virtual machine. Your actual hard drive will be fine, which is why we’re doing this in a virtual machine to begin with.
After you click it, the system may seem to freeze for some time, then the SteamOS installer will begin, and automatically install all the files it needs. This process will take several minutes. When it’s done, the machine will reboot, and briefly give you the option to start in recovery mode. If you don’t, the virtual machine will simply go to a blank screen. If this happens, reset the virtual machine (Machine > Reset), and choose to start in recovery mode while the option is available to you.
You’ll now see a command prompt, where you’ll have to enter several commands. First type apt-get purge “.*nvidia.*” and hit enter. Some stuff will scroll by, and you’ll be asked for a “y/n” confirmation. Type “y” and hit enter.
After more furious scrolling of text, you’ll again find yourself at the command line. Enter dpkg-reconfigure xserver-xorg and press enter. If you don’t get any confirmation at all, but just see another command prompt, that means it worked.
Now, we’ll need to install VirtualBox guest additions—a suite of software that essentially allows the Debian-based SteamOS to function in a virtual environment. To do that, follow these steps:
First, click on the Devices menu at the top of VirtualBox, and then click on Insert Guest Additions CD Image. (You won’t receive any confirmations that you’ve done so.) Next, type in mount /dev/cdrom /media/cdrom and hit Enter. (Note the spaces after “mount” and the first "cdrom"!) The virtual machine will say something about mounting read-only, but that’s fine.
Next, enter the command sh /media/cdrom/VBoxLinuxAdditions.run—once again, note the space after “sh”—and hit Enter again. Lines of text will scroll up for a few seconds as the virtual machine installs the Linux guest additions. When it’s done, restart the computer by entering reboot and hitting Enter.
Finally, you can boot into SteamOS. When the screen where you earlier selected recovery mode appears, choose the top option to not start SteamOS in recovery mode. This will, at last, bring you to the SteamOS desktop. It will try to connect to the internet to update Steam—if it fails, try going into the Network Settings box of your virtual machine and changing the network adapter from Bridged to NAT or vice versa.
When you successfully connect to the internet, Steam will download an update. As of publication, that update will restart your system and, essentially, reinstall the operating system all over again. Allow it to complete the automated process, and when you finally get a chance to make a decision at the very end, choose to reboot the computer.
Things finally seem to be looking up, as a brand new SteamOS splash screen loads. Unfortunately, your joy will be short-lived, as the system will now dump you on an empty black screen. To fix this problem, hit ctrl + alt + f2 to open a command prompt. You’ll be asked for a login name—enter “desktop.”
Next, enter the command sudo dpkg-reconfigure lightdm and hit Enter. Select gdm3 when you’re given a choice. Finally, type sudo reboot and hit enter to restart.
This time, you’ll have the option to log in to SteamOS. There are two options available for login—choose the top one labelled “Steam OS Desktop.” You’re now finally back at the SteamOS desktop, but you may notice that if you try and run Steam itself, it won’t open.
To fix this final problem, just hit alt + f2, and in the dialogue box that opens up enter gnome-terminal. This will open a terminal, into which you can type the magic word steam and press Enter. This should finally, actually open Steam. Accept the EULA, download any updates, and login with your Steam account.
Finally, after much finagling, you’re running Steam in SteamOS! To get the intended living room PC feeling, you can click on the Big Picture Mode icon in the upper right-hand corner to launch a version of Steam optimized for playing from the couch—the true incarnation of the much-balleyhooed SteamOS. To see your Linux-compatible games, which will work on SteamOS, open your games library in, then click the View all games button. In the library screen that appears, simply select the “Linux” option from the drop-down menu—one you won’t see in Steam for Windows—to filter out the playable titles.
SteamOS will probably be a bit laggy in the virtual machine, but you’ll be able to get a solid feel for what Valve’s gaming-centric operating system is all about.