I am trying to install Windows 7 on Asus X55C series laptop which came with Windows 8. I found Windows 8 uninteresting and instead I wanted to install Windows 7 32 bit. The disk is GPT partition first. I convert the disk from GPT to MBR by using Gparted live CD. I also disabled Secure boot. But the BIOS would not let me boot from CD or USB. The one time boot options menu brings no options at all. I went to BIOS and there is not boot order option at all. What should I do? How can I set the BIOS to use MBR instead of UEFI? Thanks in advance for your help.