Windows 7 Install Problem (can't boot from cd)

[HellnoRO]

Hello. I have a problem. My PC was built up by my friend and came installed with Windows 8. When Windows 10 came I upgraded, but now I want to downgrade to Windows 7... The thing is that whenever I put the Windows 7 cd into my computer it doesn't show me to press a key to boot, so I opened the BIOS for the first time (I pressed F2) but instead of BIOS it showed a weird GUI, with ASUS on it and clock and everything, every BIOS setting but just into a GUI and a mouse, which is also nice.
But when I looked up for what should I use to boot, the only 3 things there were:
SATA (numbers)
- (numbers)
- UEFI (numbers)
something like that...

I looked it up on the internet and it said that I may have BIOS Mode set to UEFI and the Secure Boot on, but it's not like that, they're set on Legacy and Secure Mode Unsupportable, like that:

I could also do take a photo with my phone on the BIOS GUI thingy if that's needed...
please help me

 

[Suztera]

With ASUS you may be presented with EZ mode or Advanced mode. EZ mode which is a very simplified GUI BIOS with monitoring. You can switch to Advanced mode which give you more access within your BIOS.
If you want to boot up the Win 7 disc, you can simply just go into the boot menu and choose to boot the optical drive containing the window 7 disc.