HP Slimline Desktop 290-a0512ng Bios Update failure

[HuH999]

Hello everyone,

I recently run to this type of problem:

I used the HP Support Assisstant to update my HP 290-a0512NG, and somehow the the F.36 BIOS Update is made things worse: the internal factory SSD cannot be used as an OS, because it can't be booted from there, so I installed the Windows 10 on the Internal HDD, and it cannot be switched back to the SSD. Before the Bios update the internal SSD was used as a system disk, and now it cannot function that. Furthermore, in the BIOS menu, in the storage option it's not possible to change back to SATA Simulation from AHCI. I didn't have the previous BIOS firmware, so I cannot install back that, and I do not know, how can I factory reset the whole board. Is there anything that can fix this issue? Thank you very much in advance for anyone who can help,

[WAWood]

Sorry no one has replied earlier -- but this seems like a particularly difficult issue.

Is the SSD a 2.5 inch one (like a small deck of cards) or an NVMe drive (like a memory stick)?  Asking because if it is the first, there is no reason why your PC would not be able to boot from it.  If it is the second, that could be an issue because a BIOS update resets the UEFI settings to default.  And, as far as I know, you need to use AHCI to boot from NVMe drive.