Whenever I reboot my PC, one of my HDD's just decides to remove its drive letter. I think this started to happen when I installed Linux on it but wiped it after I gave up (so maybe it still thinks it's like a boot partition so defaults to hidden). I've tried messing with disk part and while the disk is listed, there aren't any volumes to maybe remove the "hidden" attribute as I saw one solution for. detail disk with the funky drive selected gives:
Type : SATA
Status : Online
Path : 1
Target : 0
LUN ID : 0
Location Path : PCIROOT(0)#PCI(0102)#PCI(0001)#ATA(C01T00L00)
Current Read-only State : No
Read-only : No
Boot Disk : No
Pagefile Disk : No
Hibernation File Disk : No
Crashdump Disk : No
Clustered Disk : No
There are no volumes.
DISKPART>
This is what I'd expect a drive to show if it has no partitions but it does and I can access it in file explorer... All my files stay intact after reboots but I have to go into a 3rd party disk management tool (AOMEI Partition Assistant) to manually assign it a drive letter.