Thank you for contacting the Intel community.
Please bear in mind that a RAID is not a back up so you always need to back up your system somewhere else.
For you to have the Intel® Rapid Storage Technology properly working you need to set your BIOS to RAID mode and then install the operating system, if you install the operating system on AHCI mode your RAID will not work and you cannot manage the RAID using the IRST.
At this point, if the operating system was installed in AHCI mode you will need to reinstall the operating system with the BIOS set to RAID mode, right now changing from AHCI to RAID is normal because the operating system was installed on AHCI mode and not on RAID mode.
I have RAID for it to effectively be a backup inasmuch as there are two drives with the same data. I also back up all my data onto a NAS as well as cloud storage.
I have owned this computer for three years and it has ALWAYS run perfectly as a RAID drive and the software has run without issue - this is a sudden change where it will not start and both drives are showing as separate instead of showing as one single RAID drive.
If I set the BIOS to RAID then it will not start up: are you saying that I need to set it to RAID, then completely wipe my system and start over?
Before I do something so drastic, I need to know WHY this happened in the first place so that I can be certain it will not happen again. Reinstalling Windows and getting everything set up again will take at least a full day of work, probably more, so I need to be absolutely sure what the issue is that caused Intel's Rapid Storage Technology to stop seeing the drive as RAID and stop being able to launch, before I try anything else.
What do you suggest caused this?
(IVAN, to clarify, Windows was NOT installed with it set to ACHI mode - it has been in RAID mode for several years and working perfectly. I do not know why it has suddenly changed to ACHI mode. Windows has not been reinstalled on a changed BIOS or anything, it's like it has suddenly changed overnight without me asking it to and I don't know why or how).
I understand, please allow me to further investigate for you so you don’t have to do anything so drastic, let me check for information to see if there is anything else we can do before doing a whole installation of the system.
Do you have the operating system installed on another HDD? If yes, you can reinstall the operating system in RAID mode, you only need to format the operating system on the HDD you have it installed, once the operating system is reinstalled install the drivers and the Intel® Rapid Storage Technology, you can download the proper IRST for your system here:
When you install the IRST you should be able to see the RAID volume and if both HDDs show as single HDD you can create the RAID again from RST and it will ask you if you want to create it with data you have in your HDDs so you don’t lose the data.
Another thing is that if you have the operating system installed on your RAID volume and you have a partition for you RAID and the operating system installed on another partition you can reinstall the operating system on the partition you have it installed and leave the other partition where the RAID is intact, then you can do the same process that I mentioned above from IRST.
Now, if you have the operating system installed on your RAID volume and there is not partition where the operating system is installed you will need to create the whole RAID volume again.
Please let me know how it goes.
The Windows AHCI/RAID mode CAN be changed without re-installing the OS. The procedure is as follows:
1. If currently installed, uninstall your RAID or AHCI SATA driver (for intel, Intel Rapid Storage Technology)
2. Launch msconfig -> Boot tab -> select Safe boot -> Apply -> Restart
3. Go into UEFI/BIOS and set SATA mode to which ever one you want
- Windows will Boot-up into safe mode.
4. Run msconfig again -> under the General tab select the Normal startup option - > Apply -> Restart
The system should boot into windows and you can install your AHCI or RAID driver. Intel RST will work fine.
Doing this inadvertently, perhaps after flashing/updating the BIOS, could have caused the OPs issue.