[SOLVED] Wont boot from m.2, will boot from override to HDD

[OMG_its_Zach]

Im gonna try not to make this too long and complicated. So I built my first PC, upon trying to boot windows for the first time, it sent me into a bios loop. Well, I ended up fixing that, it was not reading my drives, pretty simple, I changed it to legacy and uefi. The first boot was great, booted right up no issues.
Well now, it will not boot from C drive which is the m.2. "No operating system found" It is reading that it is there and it is functioning and stores data, games and the OS. Just will not boot from it. The only way windows boots is through override to the HDD.
Im thinking when I built the computer, I had both of the drives plugged in during the first boot. May have been a mistake. At this point, the only way I can think to resolve this, is to wipe both of the drives, unplug HDD and reinstall windows, and see if it will boot then. Just wondering if theres an easier solution that Im not aware of, as I am fairly new to this, and am really only relying on information I get off of the internet.
I have already made sure the SSD (which is an nvme) is plugged in correctly, I have gone through all the CSM options, tried changing them to see if it would boot, nothing.
The computer is functioning and stable right now, its just annoying to have to go through BIOS to override everytime it reboots. Wiping drives and starting over fresh is a last resort, but its the only option that I can think of. Any insight? Thanks!!

Build:
i5 9600k
EVGA RTX 2060 super
Asus prime z390p
intel 660p 1TB m.2
seagate 2TB hdd
16gb Corsair vengence lpx 2x8gb 3000

 

[william p]

If your BIOS wasn't designed to boot from a PCIe device than it won't be looking there for an operating system. See if that MB supports Nvme at all. If it does check your BIOS version. It may need an update. UEFI and Legacy are 2 different BIOS methods. You have 1 or the other. UEFI is newer. You should use that. You didn't say what GPU etc. you have. If the video cards is forcing you to use Legacy BIOS then Nvme may not be possible in that BOIS mode..

 

[OMG_its_Zach]

If your BIOS wasn't designed to boot from a PCIe device than it won't be looking there for an operating system. See if that MB supports Nvme at all. If it does check your BIOS version. It may need an update. UEFI and Legacy are 2 different BIOS methods. You have 1 or the other. UEFI is newer. You should use that. You didn't say what GPU etc. you have. If the video cards is forcing you to use Legacy BIOS then Nvme may not be possible in that BOIS mode..

Yes it is showing as a bootable NVMe drive in the bios.
I have the latest bios flash. I have the latest firmware installed on the ssd. The drive functions, stores data, and contains the OS files, but it just refuses to boot from it. "No Operating System found" is the message i get. Im thinking I may have made a mistake by having both drives plugged in during the initial config/boot.

 

[william p]

Can you change the boot sequence so it looks for the m2 drive first? But if the boot partition wasn't created on it then you need a do over.