Correction. There *must* be a space between bcdedit and the forward slash. There is no command called "bcdedit/set" (for good reason)

Good information and thank you - it worked nicely. :)

this works, thanks

I used the ALT commands

Ummm... don't you think going to msconfig and just checking Safe Boot or un-checking Safe Boot is an easier way to, I dunno... make it so people don't mess anything up?

This approach worked on my Windows 10 machine - which should have been set up with AHCI in the first place since all of my drives are SSD. However one must know that it may take several reboots for your D: disk to re-appear and become stable. In the first reboot, my data appeared to have been lost. After swearing at the computer several times, I decided that perhaps a reboot would help the situation. Fortunately after 2 more reboots, the disk re-appeared and all of the data was intact.
Thank you for these steps to switch my computer from RAID to AHCI.

Added a Samsung 970 Evo (500GB) NVMe M.2 alongside the existing HDD in new Dell Inspiron 5570. Samsung software couldn't load the drivers because drives configured for RAID. I set AHCI in BIOS and W10 (home) wouldn't boot up. Returned to BIOS to RAID and rebooted successfully. Found this thread and tried it. Yes, it worked! It took a bit of work to manipulate the the drive letters afterwards but got there eventually. Thank you for the information.

I had a really odd experience attempting this on Windows 10, but I finally figured it out:
When I switched to AHCI and got to the safeboot menu, my keyboard wouldn't work. If I tried to get to the keyboard settings nothing happened. I was able to get to the Command Prompt terminal via the 'Windows Systems' tab in the Start Menu. Once I had opened the Command Prompt, I could type in it using the on-screen keboard (Start Menu -> Settings -> Ease of Access -> Keyboard (scroll down and it's on the left) -> On-Screen Keyboard). Then I typed bcdedit /deletevalue safeboot (there didn't seem to be a way to use curly brackets). Then I Rebooted, and found that I had left Safe Mode, and everything was back to normal :)

It's one hell of a work-around, but hopefully this helps somebody!

Thanks @Evan! The keyboard thing also happened to me, but using the virtual keyboard did the job. If you press the shift key you'll be able to use curly brackets!

Thank you very much! I am running Server 2016 and didn't realize my Intel board was in IDE until I tried to run two SSD's in Raid0 and was only getting about 400MB/s. I switched to AHCI and was getting "Inaccessible boot device". I used the method described above and it's working now! 1100MB/s.

@ bob and anyone else. To put this simply, this isnt for people with an Active raid array, its for people that have an incorrectly configured bios setting. If you have an active raid array (Raid 0 or some variant there of) this is not the solution for you.

Worked perfectly on a Dell Inspiron 15 7586. Came pre-configured in RAID mode and updated to 970 EVO Plus without the ability to get the Magician to function.
As soon as I completed the operation which took about 3 minutes, everything worked perfectly with no glitches or issues

hello home this line does not work :bcdedit /deletevalue {current} safeboot (ALT: bcdedit /deletevalue safeboot)
I have : the specific delete command is not validated

Hi Marc, you need to use one of those commands not both at once I think, hope that helps

work perfectly on my DELL XPS 15 9550 with Drive Model: THNSN5512GPUK NVMe TOSHIBA 512GB
Great
Thanks

Saved my day. Alternative command is somewhat confusing. I used bcdedit /set {current} safeboot minimal and bcdedit /deletevalue {current} safeboot
Result is that W10 booted with sata settings set to AHCI, Happy!

Thanks for sharing!

Saved my bacon!
I got my ageing (10yrs) Dell T5400 back into life using the full commands.

Very many thanks!