I have an 8500 Spec with the 256 SDD that gave me the same error the first 5 or 6 times I booted it with the installed Win8. I kept hitting F1 and eventually it would boot. It stopped doing it and has booted OK for several weeks but I have no idea what caused it. My problem is that it will only boot from the SDD. I can not boot using a DVD, CD, USB drive - Set up shows it is using Windows Boot manager and if I change it nothing starts.
Dell was no help - I swore I would never buy another Dell after my XPS GEN4 "experience" -- I wish I had not gone back on it.
The only thing I noted as being different when it stopped giving me the error is that Win Upd had put a lot of updates on the machine (although I would not think it to be a Win issue), I upgraded to win8 pro and I had changed the keyboard and mouse from the OEM to Logitech wireless.