Unable to change external drive letter

I have two WD My Passport 2TB external drives operating via USB 2.0 ports on my Qosmio Laptop.

I have no problem changing the different drive letters individually. Lets say the black one is allocated Drive F. When I disconnect the black one, and connect the silver one, it thinks it is Drive F too, so I rename it to G, then disconnect it and reconnect the black one only to find it is now G as well.

When I connect both to the laptop, the first one connects as say Drive F but when I connect the second one as well, it seems to think its F also but the Drive letter cannot be changed while both are connected. I also can only read the first drive, and the second one has no drive letter assigned to it.

The silver one is formatted to Fat32 and the Black one if formatted to NTFS although I don't believe that matters.

What I would like to do is copy all the files from silver to black, then format the silver one to NTFS.

Any suggestions?

Found this on another site:

Solution found here, thanks to Win7Survivor.

Thank you all

Perhaps you found the solution here Two External Hard Drives, Only One Shows - thanks to bmacleod - and did a copy and paste.

Never mind, you found the solution and resolved your problem. Good.

This is a very common problem encountered by those who buy two or more identical drives of the same manufacturer at the same time..

Windows identifies a drive by a Unique ID in sector 0. When two drives have the same Unique ID as it may happen in these cases, Windows will identify only one drive and the other drive will be "offline" due to "Signature collision"

And you bring the other drive "online" as you did, Windows assigns a different Unique ID to that drive and thereafter that drive becomes accessible to take a different drive letter.

Spot on Jumanji, thank you.

Barry