The F drive does not show on any explorer when the 128g thumbnail is in, but does when the 64g or a card reader is plugged in.
Answers (1)
My first guess is the drive has no format. Go to tucows.com and search for "partition". I like "Easeus".
A hard drive must have at least one partition defined, and it must have a format that your OS can use. A partition program will display all that information and make the neccessary changes.