Fill in the blanks...

not formatted error message means....

not recognized error message means....

I have never understood the difference between the two error messages when it comes
to USB memory drives connected to Windows OS.

Can anybody shed some light on them?

The not formatted means that the controller is giving the PC info that it is indeed a drive, but somehow the data on the NAND specifying the FAT or MBR has become erased or corrupted, or the controller is corrupted, but not to the point of totally borking the connection.

The unrecognised is more lower level, cant read the device ID, or the drivers cant interact with the device enough to identify it, or read enough info to work out how to interact with it.

I may have terminology skoo whiff or be a bit vague, but thats basically what you are looking at.

an unrecognized device could be a shoddy power supply, too many devices on a whimpy USB port of a laptop or dodgy USB cable for example.

the many flames stating the actual technical explanations to show how dumb I am to follow will be worth reading too

Cheers

Agreed - "not recognised" is a USB / electronics problem e.g. enumeration failed; "not formatted" means the device has been successfully enumerated as MSD, but Windows couldn't mount / recognise the filesystem (more than one type of fault can cause this message - it's a general "catch all").