Using a known, bootable CD / DVD, the machine will not boot from CD and only boots from the hard drive. The CD is ignored during boot
In the BIOS, it appears you can change the boot order, but the order does not take effect.
Newer machines have a new style of motherboard/disk interface called UEFI. A Unified Extensible Firmware Interface allows the BIOS to interact with larger hard drives and adds security to the Master Boot Record via a signed Certificate. This keeps RootKits from infecting the boot device. This works hand-in-hand with Windows 8. Other capabilities can be found in this Wikipedia article.
With the new UEFI Secure Boot, you cannot boot with an un-signed CD. Vendor bootable disks, such as Acronis's Recovery Disks must be signed (certificates) by the vendor before they can be used on a Windows 8 machine (see below).
You can boot from a legacy CD by making the following changes to BIOS. These changes should be considered temporary and you should return the BIOS settings to their Secure Boot mode when done.
With these BIOS changes, be aware you can boot from a legacy (unsigned) CD/DVD, but the C: drive will not be available.
If you need to boot from a CD/DVD *and* you need to access the C: drive, then you must get a signed, bootable CD. If you have made your own PXE bootable disk, getting a signature from Microsoft is beyond the scope of this article.
Legacy Boot Solution:
Changing Boot Order
See important note, above.
These instructions were written using a DELL 15Z laptop with a secure-boot bios, American Megatrends BIOS version A00.
1. Ensure a bootable CD/DVD is in the drive before starting these procedures.
2. Boot the computer.
At the Dell BIOS splash screen, insistently and repeatedly but not wildly, press F12 until the BIOS menu is displayed. Be aware on newer (2013) Dells, there is no prompt on the BIOS splash indicating F12 is an option.
3. Choose "Change Boot Mode Setting"
4. Change the Boot Mode to "Legacy Boot Mode, Secure Boot Off". The computer will reboot once selected.
5. Again at the BIOS splash screen, note the changed menu.
Press F2 for Setup.
(or, if F12, choose "BIOS Options")
6. On the top-menu, arrow horizontally to "Boot". These are the old-style boot menus that many of us are familiar with. Change the Boot Priority
Set #1 to be CD/DVD/CD-RW Drive.
Set #2 to the Hard Drive
No opinion on other settings
7. Press F10 to save and allow the workstation to reboot.
8. The CD/DVD should boot.
You may be presented with a sub-menu. For example, Acronis Disk Image prompts to boot into Acronis or into Windows.
Once you are done with the bootable CD/DVD, return to the BIOS screens and return the Boot Mode Setting to "UEFI Boot Mode, Secure Boot On". I do not recommend staying with the Legacy Boot Mode and nor did I test booting into Windows with that setting.
With these changes, my Acronis True Image Backup CD (Version 2013) would boot into the application. But the software could not see the newer UEFI Hard Disk. The solution was to upgrade to Acronis 2014..
For older versions, Acronis had a hotfix http://forum.acronis.com/forum
Related Keyliner Articles:
Acronis 2010 / 2011 hangs in Windows 8
Acronis 2010 Step-by-Step
Acronis 2010 Recover a single File from backup
Acronis 2010 Not the last disk in backup
Disk Imaging Cleanup Steps - Faster backups
USB Backup Drive Slow