I actually got this error (image below) sometimes (not always), which means my hardware is fine (?).
Everytime I got this error I tried a walk around by starting the VM inside HyperV Manager (After upgrading to Windows 8.1, unable to run Windows Phone emulator without memory error).
But now, even when I started it, it still didn't work (image below).
The errors occurred when I started using Application Deployment to test a xap file in WVGA (not WVGA 512 MB) emulator, the emulator didn't start and after that whatever version of Emulator I tried, the same error appeared.
I tried deleting all the VMs in VM Manager and then started VS and run the emulator again but it still didn't work. I also restarted windows but the problem remained unsolved. I'm using VS2012 and Windows 8.1.