If you changed to AHCI in the BIOS and it was set to RAID when Windows was installed, then the system will not boot into Windows. If the system is looking for a flash drive as the 1st boot drive then access the BIOS and make sure that Windows Boot Manager is listed first. Also set the BIOS back to RAID. Assuming that you are not booting into Windows correct? 

Those are new hard drives and non of them is listed anywhere even when I am trying to install a new windows on the computer.

I tested the HDD and NVME on another computer they are working fine.

From reading your post, I can understand there are 2 issues with your Optiplex 7080:

1. NVMe and HDD did not show in BIOS and during Windows installation.
2. System is throwing an error message and alert sound.

For better assisting and more accurate in identifying the issue, would you provide your system hardware settings and the goal of what you plan to achieve. 

Let start off with a better description of your Optiplex, which form factor do you have, mini tower, small form factor?  How many drive in the system and what type, solid state, hard drive, NVMe, SATA?

What is the reason for Windows installation?  To repair, to upgrade, change RAID settings?  What operating system was installed before?  What is the condition of the system now and what do you want to achieve?  

These questions will help to better analysis of the issues as well as selecting proper system settings and installation method.  I guess that the system threw a message about no bootable device found, but if possible, would you post a picture of the error and describe what was the flash drive you used.

When we get to point the 7080 can see a drive, be sure only one is connected when installing Windows.  Or did you load a bootable drive on a different PC?