3 Acronis compatibility see here
1 Bet the drive is Ok
Bootable media from previous versions of Windows may not be recognized in Windows 8. You can change the Boot Mode setting from UEFI to Legacy BIOS, and it should recognize the bootable device.
Use the following steps to change the Boot Mode:
Completely shut down your computer. Power on the system. As soon as the first logo screen appears, immediately press F2 to enter the BIOS. Use the right arrow key to select Boot. With Boot Mode highlighted, press Enter, and then use the down arrow to Press Enter. Press F10, and select Yes to save the change and exit the BIOS.