[SOLVED] Boot Drive does not show up in BIOS

[Matticus12]

I built my PC myself. These are the components I had and everything runs completely fine:

Asus Prime Z370-A II Motherboard
I5-9600K Processor
Seagate Firecuda 2TB Solid State Hybrid Drive
Corsair 16GB DDR4 3200MHz

For Xmas, I got an I9-9700K and I installed it but my boot drive would either not show up in BIOS or Windows would just not boot. I figured maybe it had something to do with the motherboard not shifting settings to the new cpu so I put the I5 back in and everything worked fine again.

I just bought a Asus ROG STRIX Z390-e Gaming motherboard and installed the I9 and it is doing the same thing. Entering BIOS, nothing shows under Boot Priority. In the BIOS, if I go to Advanced\PCH Storage Configuration, SATA6G_2(Black) does show my hard drive but it's just not pulling it to boot Windows. Is there some setting that I'm not doing? I tried a lot of things when I got the CPU but nothing worked and I hoped the motherboard would do it but, it didn't and I'd rather not have to buy a new hard drive and reinstall everything.

Any help would be much appreciated and I'd be happy to answer any questions. Thank you.

 

[Mr.Spock]

check the bios revision for both motherboards.

the same revision should support both CPUs but doesn't hurt to double check.
for the 2nd motherboard it may pay to check if IDE/AHCI settings are correct since the SATA device is recognized

also check for a trusted boot setting, it may be disabling all other devices on boot and using the preferred device.

if it's happening on both it might be the CPU

I built my PC myself. These are the components I had and everything runs completely fine:

Asus Prime Z370-A II Motherboard
I5-9600K Processor
Seagate Firecuda 2TB Solid State Hybrid Drive
Corsair 16GB DDR4 3200MHz

For Xmas, I got an I9-9700K and I installed it but my boot drive would either not show up in BIOS or Windows would just not boot. I figured maybe it had something to do with the motherboard not shifting settings to the new cpu so I put the I5 back in and everything worked fine again.

I just bought a Asus ROG STRIX Z390-e Gaming motherboard and installed the I9 and it is doing the same thing. Entering BIOS, nothing shows under Boot Priority. In the BIOS, if I go to Advanced\PCH Storage Configuration, SATA6G_2(Black) does show my hard drive but it's just not pulling it to boot Windows. Is there some setting that I'm not doing? I tried a lot of things when I got the CPU but nothing worked and I hoped the motherboard would do it but, it didn't and I'd rather not have to buy a new hard drive and reinstall everything.

Any help would be much appreciated and I'd be happy to answer any questions. Thank you.

 

[Matticus12]

Thank you. I was actually able to fix it by going into Boot in the BIOS, then Enable CMS and change UEFI to Legacy Only. Rebooted and it loaded Windows.