Follow the steps in the following link.

https://superuser.com/questions/1280141/switch-raid-to-ahci-without-reinstalling-windows-10

Also

https://www.ryadel.com/en/windows-10-enable-ahci-change-raid-ide-hdd-ssd-how-guide/

https://www.youtube.com/watch?v=9ngnIKqPOc4

I was not fast enough to edit my previous post Here below is the complete one I wanted to post.

@JOcean, thank you a lot for your links to effective solutions! The one from SuperUser still works.

Just to mention that I used to apply the following and simpler solution in the past but for changing from Legacy (PATA) compatibility mode to AHCI mode. It should work for any change between RAID, AHCI and PATA/IDE Compatibility modes provided the value data are set correctly in the registry.

Solution for Windows 7: https://answers.microsoft.com/en-us/windows/forum/all/changing-from-raid-to-ahci/4c94f678-6bd1-48a6-b871-8872c841023a

Based on the Microsoft KB article: http://support.microsoft.com/kb/922976

With the following registry keys to be changed for Windows 10:
 - HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\atapi
 - HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci (instead of msahci that does not exist anymore in Windows 10)

@JOceanthank you a lot for your links to operational solution ! The one from SuperUser still works!

Dear Peter,

if changing the values of these registers won't break the windows?

Highly appreciated your support.

Regards,

Hello Pharonic,

Sorry I just saw your post today, almost one year later. Just in case you are still looking for an answer, this answer is the following: changing these registry values to some not matching your hardware and/or BIOS/UEFI specifications WILL BREAK Windows at least temporarily.

Windows won't boot till you fix the issue. But such a wrong registry edit won't damage or corrupt any system file or data. It will just prevent Windows to boot because the system won't be able to find a drive to load the OS from..

Have a look at those brief Microsoft articles to understand how the ControlSet registry keys are related to system drivers, hard drive in particular:

• HKLM\SYSTEM\CurrentControlSet\Services Registry Tree => https://learn.microsoft.com/en-us/windows-hardware/drivers/install/hklm-system-currentcontrolset-services-registry-tree
• Set startup types of many services once and for all => https://answers.microsoft.com/en-us/insider/forum/all/set-startup-types-of-many-services-once-and-for/83c14b73-d885-4ca9-a4a3-a0b33eadb7d3

Hope it still helps!