Everyone has a full backup in case that happens. I don't see why anyone would tinker with this.
New Dell XPS 8930 computer, Main drive/operating system is on PCIe, but all my files reside on a Samsung SSD. While poking around in BIOS concerning an odd problem, I see "SATA Operation" is set to "Raid On", rather than AHCI. There is no Raid set, of course, each drive runs separately. However, just out of curiosity, on the Samsung SSD, when I right clicked on "Format" the notification said "drive was being used" (how?)
Going back to BIOS, when I went to switch from RAID to ACHI, I get the dire warning that my computer may be unbootable, etc.; are you sure...
I didn't change anything, but would anything bad happen if I switched it to ACHI?