I'll keep to my old HP which had some multi-memory card reader. HP had to make some app to hide drive letters when there is no media.
My first google was https://www.google.com/search?q=hide+drive+letters+when+there+is+no+media
But let's refine this: Read the next link and read about "you can use the TweakUI Powertoys to hide drives from appearing in Explorer. " LINK: https://superuser.com/questions/34211/flash-card-reader-how-to-hide-inactive-drives-letters
When I open My Computer under Devices With Removable Storage I have my DVD (optical) device displayed, two usb memory sticks displayed correctly BUT also FIVE non existing empty devices displayed eg Removable Disk (P which has a capacity of 0 bytes.
Why do they appear and can they be removed - I tried Disk Management tool but it does not display them.