I have a SATELLITE PRO L850-1KM and have a problem booting up from CD/USB. I've burnt a fresh Windows 7 cd as I didn't want the preinstalled Windows 8 crap but when I hold F12 and go to the boot options it says 'Media Check: [Fail]'. I can hear the CD spinning up but it doesn't work. I've also tried a bootable USB stick! It's asif Toshiba don't want you to install your own OS.