Can't boot from CD (w-8.1) Missing Logon password

Have a Gateway Desktop. Upgraded from 8 to 8.1.
Somehow I disabled the disabled Password Logon and its back asking for a password at boot.
Owner doesn't remember original password when setup.
I have a password blanking cd that I've used on both 8 and 8.1 pc's.
The problem is I can't boot from the CD and I can't, obviously, use that wonderful new setting, "Update", "Update and Recovery" and the option to boot with USB, CD etc. since I can't access the OS.
I have the BIOS set for the CD/DVD drive for first boot however boot options only show the "UEFI: ST....." drive.
So I can't boot from within or without.

Pete

Never mind.
Found the CSM to boot into Legacy boot and was able to see the boot order.
Thanks to those who thought of me before answering.
Pete

BTW, I use Spotmau for a password reset, among other things.
Hasn't failed me yet.

Sorry nobody got to you in a timely fashion, ya know black friday and stuff - But thank you for the reference to Spotmau, I'll check it out. I've been using Windows Offline Password Reset for ages, but I don't know how well that will work when dealing with MS accounts.

Yah this new "UEFI BOOT" that you can only get to from WITHIN Windows 8/8.1 is a major clusterf___. But usually most laptops and desktops CAN be forced into BIOS setup by an Fkey. I just set up Windows 8 an a brand new HP laptop, and it was the same deal, but fortunately, I could still use the F10 key to get into the BIOS.

Its like Microsoft handed us this alleged "Modern Operating System and they expect us to repair it from within the GUI, but even they know you CANNOT repair it like that sometimes.

The F 12 worked, however, only the "UEFI: ST...." showed up in the resulting window.