HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices4. To Change a Drive Letter
A) Right click on a listed /DosDevices\(drive letter) (Ex: /DosDevices\D: ) that you want to change the drive letter of, then click on Rename. (see screenshot above)5. To Remove a Drive Letter
B) Rename it with a drive letter that you want to use, and is not already listed here, and press enter. (see screenshot above)
For Example: If I wanted to change it from D: to K: , then I would rename it to /DosDevices\K: instead.
A) Right click on a listed /DosDevices\(drive letter) (Ex: /DosDevices\D: ) that you want to remove the drive letter of, then click on Delete. (see screenshot above)6. Close regedit.
B) Click on Yes to confirm the deletion. (see screenshot below)