I have one suggestion, This could be related to UEFI settings in the BIOS.
Here is a example from this page: http://superuser.com/questions/524598/asus-uefi-bios-options-how-to-boot-from-dvd
To get the DVD drive to show up in the boot menu, you might need to go into the BIOS (actually (U)EFI Settings) and enable Legacy (BIOS) Mode or the UEFI Compatibility Support Module (CSM) or similarly worded option:
I had to do this type of setting with a Windows 8 ASUS laptop.
I left Windows 8 on it and installed Classic Shell http://www.bleepingcomputer.com/tutorials/start-menu-in-windows-8-with-classic-shell/
Windows 8 no longer includes the traditional Start Menu that Windows users have become associated with using. Instead they replaced it with a new interface called the Windows Start Screen that many people find to be not as intuitive as the traditional Start Menu. This is especially the case if you are not using a touch screen. With this in mind, a free program called Classic Shell has been updated to support the ability to add a Start Menu to Windows 8.
With the addition of Classic Shell I Like Windows 8 as much as Windows 7 and it avoided the pain of starting over and using up a spare Windows 7 License & disk I had bought a while back. I like the way some of the Windows 8 features work better too.
I am doing 95% of my online work in Windows 8 these days and reserve My Win7 Tower for Video work only.