It came with an OEM install of Windows 8, filled with garbage software, as usual. I am used to this--step 1 is always blowing away the junk OS ruined by the OEMs and installing my own.
Besides, I really wanted Server 2012, not Win 8. So I decided to dual-boot the thing.
I went into Disk Management in Windows 8 and found an empty DATA partition, so I shrunk that and made a 50 GB partition named Srv2012 to take Server.
I had a Server 2012 ISO from DreamSpark, so I made a bootable USB stick following these instructions:
Then I booted the ASUS from it, and tried to install Server, but got this error message:
The product key entered does not match any of the Windows images available for installation. Enter a different product key
Apparently the OEM Win 8 product key is stored in the BIOS and prevents you installing anything else.
I found these instructions and Microsoft's KB 2796988 which say the problem can be solved three ways:
So I had to make the autounattend.xml file.
I started from
these instructions, but was able to skip steps 8 through 18, because I wanted to control the partitions manually.
I also skipped steps 20 through 24.
I saved the file as autounattend.xml in the root of my USB stick, and it worked! I ended up with a Windows 8 / Server 2012 dual-boot.
The only remaining problem was that it installed Server Core, without the GUI, and did not let me choose anything else.
So I just added the GUI back in using these powershell commands.
It was a lot of work, so I'm saving it here to guide others, and also so I can remember it myself.