ok i have the Samsung xp941 m.2 SSD in Slot 5 of my Asrock mobo, running in Gen 3 speed, data is on it (thankfully nothing important)
So, the SSD itself for some reason stalls halfway through a filecopy, so i think its my crappy USB 3 hub, but that's not it, wait.
So the ASROCK UEFI allows you to switch the PCI-E slot between GEN2 and GEN3 speed.
So, i switched the slot 5 with the SSD in it to Gen 2.
back to windows, nooooo its gone! But wait its in Disk management...