Switched SATA settings from RAID to AHCI, broke computer.

So after the change pressing F2 does not get you into the BIOS? Try resetting the BIOS by removing the CMOS (coin cell) battery from the motherboard. Leave it out of the system for at least 15 minutes (Intel suggests 30 minutes). Then reinsert the battery and try again.

https://www.dell.com/support/article/us/en/04/sln284985/how-to-perform-a-bios-or-cmos-reset-and-or-clear-the-nvram-on-your-dell-system?lang=en

Plus these Dell support pages on a no POST symptom.

https://www.dell.com/support/article/us/en/19/sln151805/how-to-troubleshoot-a-no-post-issue-on-a-dell-notebook-pc?lang=en

https://www.dell.com/support/article/us/en/04/sln292599/resolve-no-power-no-post-no-boot-or-no-video-issues-with-your-dell-computer?lang=en

Yah, what JP said. 

There's no settings in the BIOS that would prevent the BIOS from coming up. Which begs the question, why were you in the BIOS changing settings? Short of coincidence, the only way I can think of this happening is if you were flashing the BIOS and somehow interrupted it. 

Why were you playing with your BIOS? 

In case you don't know, you need to start tapping the F2 key frequently and earlier than you would expect.  But changing the SATA controller would not normally stop you from getting into the Bios..

If it is going into a black screen, it may already be past the Bios and in some type of recovery process.   I believe if the Bios had become corrupted, you may get a black screen but the system seems to shutdown shortly after.  I only say this because some folks have had the experience.

Hope you already made a Windows 10 installation USB or DVD. If so, insert the USB and power off and on, and fresh install Wndows 10 will do. I tried this way and it worked. By the way, AHCI seems superior to RAID which is Dell's preference. Don't know why?

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@Sound of silence wrote:

Hope you already made a Windows 10 installation USB or DVD. If so, insert the USB and power off and on, and fresh install Wndows 10 will do. I tried this way and it worked. By the way, AHCI seems superior to RAID which is Dell's preference. Don't know why?

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RAID is Dell's factory default for versatility reasons.  Back when Windows 7 was available, RAID allowed running Windows 7 on an NVMe SSD, which wasn't otherwise possible.  RAID is also required for systems that use Intel Optane or its predecessor Intel Smart Response, where a small SSD is used as a cache for a spinning hard drive.  And even in system setups where RAID isn't necessary, it doesn't have any downsides that affect Dell or its factory setup, so I suspect it's just easier to standardize on that across the board.  The downsides of RAID are:

- It doesn't work with Linux, but Dell sells very few laptops with Linux pre-installed (and those would come in AHCI mode).
- Depending on how new the system is and what version of Windows you're installing, you might need to manually provide the Intel Rapid Storage driver during a clean OS install.  But most people don't do that, and Dell of course can handle that with their automated factory builds, so that's not an issue for them.
- Certain SSD utilities require AHCI mode, because RAID mode causes the Intel Rapid Storage controller to abstract the storage from the OS.  Samsung Magician is an example of a utility with this requirement -- but Dell doesn't offer that utility, and Samsung Magician only works on Samsung's retail SSDs, not the ones they send to OEMs like Dell.

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@jphughan wrote:

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@Sound of silence wrote:

Hope you already made a Windows 10 installation USB or DVD. If so, insert the USB and power off and on, and fresh install Wndows 10 will do. I tried this way and it worked. By the way, AHCI seems superior to RAID which is Dell's preference. Don't know why?

---

RAID is Dell's factory default for versatility reasons.  Back when Windows 7 was available, RAID allowed running Windows 7 on an NVMe SSD, which wasn't otherwise possible.  RAID is also required for systems that use Intel Optane or its predecessor Intel Smart Response, where a small SSD is used as a cache for a spinning hard drive.  And even in system setups where RAID isn't necessary, it doesn't have any downsides that affect Dell or its factory setup, so I suspect it's just easier to standardize on that across the board.  The downsides of RAID are:

- It doesn't work with Linux, but Dell sells very few laptops with Linux pre-installed (and those would come in AHCI mode).
- Depending on how new the system is and what version of Windows you're installing, you might need to manually provide the Intel Rapid Storage driver during a clean OS install.  But most people don't do that, and Dell of course can handle that with their automated factory builds, so that's not an issue for them.
- Certain SSD utilities require AHCI mode, because RAID mode causes the Intel Rapid Storage controller to abstract the storage from the OS.  Samsung Magician is an example of a utility with this requirement -- but Dell doesn't offer that utility, and Samsung Magician only works on Samsung's retail SSDs, not the ones they send to OEMs like Dell.

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Thanks. Can you please explain in plain step by step how RAID can be switched into ACHI? 

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@Sound of silence wrote:

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Thanks. Can you please explain in plain step by step how RAID can be switched into ACHI? 

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You go into the BIOS Setup, find the setting (normally under a "SATA Operation" section heading today, but that might get updated given that it affects NVMe SSDs), and switch the setting.  But again, this is normally something you do only before you perform a clean install of a new OS, because it will render existing solutions unbootable.  If you want step by step guides for how to switch that setting and keep an existing OS installation usable, then I'm not the right person for that since I've never done that.  I've heard there are guides like that, though.

Open msconfig.exe and set your system to boot into Safe Boot on the boot tab.  Reboot and go into the Bios and change the SATA controller to AHCI.  

Allow the system to reboot back into SAFE Mode.  Use msconfig.exe to change back to a Normal startup on the General tab. 

Reboot and the system should boot back into Windows.  If something were to go wrong, reboot into the Bios and change it back to RAID.

I changed the BIOS from RAID to ACHI and the laptop would not load and Windows 10 states it was unable to load and try to recover.  It kept saying that Windows 10 could not be loaded.  I reverted back to RAID and it started working again.  You have to press F12 during booting and you will have access to the BIOS.  I'm attempting to clone the SSD to a larger SSD (Samsung) but unfortunately Samsung doesn't support RAID cloning.  I have a Lenovo and changing RAID to ACHI worked so I don't understand why a Dell laptop would not do the same.

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@Merl.mayhem wrote:

O dell inspiron m6800, 250gb ssd & 250gb hdd

i went into bios settings and switched SATA settings from RAID to AHCI.

now it will not boot to hdd or ssd.

Now i can no longer reach boot options screen, system diagnostics, bios settings etc... I just get a black screen with power on.

I have the exact same thing, but the other way around. After changing the BIOS setting from AHCI to RAID, Windows (10) presents a BSOD. Which is obvious. So just reboot the machine and change the BIOS setting back should remedy the problem. Only problem: there's no longer a BIOS around. After pressing the power button, the fans come on and that's it. No beeps. No screen. No keyboard lights. Nothing. Powering off / on doesn't do anything. In fact, even the power light in the power switch doesn't light up anymore. Only the fans work. Pulled the battery - only for a couple of minutes. No difference. Cleared the BIOS setting with the designated jumper. And now it doesn't do anything at all. Not even the fans run. Only thing working is a yellow LED on the mother board. Disconnected all peripherals, pulled out the graphics card, memory, Wifi-module and SSD module. Nothing. Dead as a dodo.

Ok, so looks like the mother board gave up. No worries, I have another XPS 8500. Made sure it runs fine. Then reboot into the BIOS and also on this machine changed the setting from AHCI to RAID. And guess what. After the expected BSOD, like the other one, it no longer works. No screen. No beeps. No keyboard lights. No way to get into the BIOS.

Seriously? Changing a BIOS setting renders a machines useless? This can't be. There must be a way to get it going again, so please tell me what to do?

Simon

Didn't you ever Open your bios settings ? 

How can he lern about bios config without Open it an lern of his mistakes!

regard,

AxelEric.

@Merl.mayhem, @Simon Weel I ran into the exact same issue with XPS 8920 desktop. Did you manage to find a solution?