Hi smikilag
If I understand you correctly you did not enable AHCI in Bios prior to W10 Installation.
To resolve this issue, enable the AHCI driver in the registry before you change the SATA mode of the boot drive. To do this, follow these steps:
Exit all Windows-based programs.
Click Start, type regedit in the Start Search box, and then press ENTER.
You can also press the Windows key + R and that will also open the registry editor.
If you receive the User Account Control dialog box, click Continue.
Locate and then click one of the following registry subkeys:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\IastorV
In the pane on the right side, right-click Start in the Name column, and then click Modify.
In the Value data box, type 0, and then click OK.
On the File menu, click Exit to close Registry Editor and reboot the system.
Upon REBOOT, Check in Bios that AHCI is enabled. The correct drivers will be installed.
It is advisable to backup your registry prior to this so that if you make a mistake you can restore your system.