Windows 11 doesn't boot after enabling RAID on BIOS

Had the same issue and the solution is as follows:

1. Using msconfig set the boot option to safe boot
2. Reboot and load the BIOS (with MSI should be via pressing delete)
3. In the BIOS, under Advanced Mode, go to settings, Integrated Peripherals and change the SATA Mode to RAID

Now I don't remember if you will need to reboot back to the BIOS or you can do the next step right away...

4. Under the RAID settings (should be same location in the BIOS settings you went to step 3), you will need to disable VMD Global Mapping and disable any Root Ports Mapped (technically you only need to disable this for the boot drive, but probably easier to just disable all of them for this step)
5. Now save and reboot to Windows and Windows should load in safe mode.
6. Using msconfig set the boot option back to normal and reboot.
7. Install in Windows, Intel RST and using that map the VMD ports and create you RAID array there.

Basically... While I am not technically savvy enough to know exactly what is happening, my understanding is turning on RAID mode usually just requires Safe Mode for windows to recognize that, however the VMD mapping is changing something with how the system sees all the drives as there is another layer of sorts between the system and the drive and windows can't figure it out automatically. By disabling the VMD mapping, the drives appear to windows in a way it can load (needs to be done in safe mode where Windows will update the necessary registry setting). Once Windows is loaded you can then run Intel RST to do the VMD mapping via their app which provides Windows with the correct drivers/info it needs to recognize the new configuration properly. - I am sure someone else more knowledgeable can explain technically more correct what is happening, but end of the day my steps should work.

End result should be getting your RAID set up as expected and everything running properly.

So, is the M.2 slot you have the NVMe drive in a dual use slot that can run an NVMe or SATA M.2 drive? If it is and you want to run the RAID, the latest Intel RAID driver can be used to run the NVMe drive so you could also run the RAID.

If you need to change a controller for a boot drive, you need to go through the process of using Msconfig.exe to set the system to boot into Safe Mode. Then reboot and go into the Bios and change the controller. After that is done, allow the system to boot into Safe Mode and then use msconfig.exe to set the system back to a normal boot. This only works if the M.2 slot is SATA capable.

Motherboard MSI MAG B760M Mortar WIFI

Intel i7 processor 13700KF

2x16GB Corsair Bengeance DDR5

M.2 drive is Samsung 970 EVO Plus 1TB

ASUS TUF Gaming RTX 3060Ti

None of the old drives have OS installed - they were data storage in my old system

Hi Dan,

My name is Igor, it's a pleasure for me to help others and I'll do all my best to help you.

Seems it is needed to ask PC/motherboard support for the help, this may be a BIOS problem.

But I have to note, and sorry if I disappoint you, RAID1 does not protect data from possible loss, it increases fault resistance only.

In other words, if one drive will fault, RAID1 will be helpful. If there will be a data corruption due to some hardware or software fault, both drives will be affected.

If you want to protect your data, make at least two copies of your data on different external drives and do not keep they connected to the PC. Connect only for data updating.

And ideally it would be better to keep one of this drive in another house.

You don't give you system model number, but on some systems, changing to RAID in the Bios converts the M.2 slot to SATA.

If any of the older drives had an OS install, that might also be involved.