Renaming Drives in RAID 1 Configuration - Necessary Drive Letter Shows

I have a dual Raid 1 configuration with (2) identical 500GB (C:) and 1TB (D:) drives. When connecting my (2) external hard drives, one of which needs to be named (F:) (I have numerous files, folders, icons and programs linked to it), I see that (E:) and (F:) are the only two drive letters unavailable for use - presumably because they have been allocated as the invisible/dynamic? drives for (C:) and (D:), respectively. How do I know which one's RAID Mirror is? And can I just rename that drive so the letter becomes available without interrupting/changing/affecting the RAID configuration? Thanks in advance for anyone that can offer insight.

Welcome.

Have you checked to see if either your CD/DVD drive(s) or perhaps card reader drives aren't using those letters?
I have never seen the system allocate additional drive letters to RAID components except the primary, in your case C:.

pbcopter said:

Welcome.

Have you checked to see if either your CD/DVD drive(s) or perhaps card reader drives aren't using those letters?
I have never seen the system allocate additional drive letters to RAID components except the primary, in your case C:.

Sorry, should have included that information initially - yes, the (2) Blu-Ray/CD optical drives (#0 and #1) are allocated to I and J, respectively. That is the thing, when I click on either E or F in the Computer Management screen, it has them labeled as Disk 4 and Disk 5, respectively, and states that they are Removable, No Media but when I click on properties tab to check on which one would be the 500GB and which one would be the 1TB one, it just says their Device Type is SD/MMC USB and Partition Style is Master Boot Record.

That would indicate that they are Card Reader drives (SD/MMC USB). Just change them to unused letters in Disk Management.
That should allow Windows to assign your external drive to E: and F:

That is very great news, thanks. I wonder why they are the only (2) drive letters that show as unavailable? Also, just to be clear, would it be accurate to say that:
(+) the (2) respective invisible RAID mirror drives are essentially unseen by the system(s) in that they are not assigned drive letters (since E and F are card readers)
(+) since they are essentially invisible, there is no actual way to verify that the mirrored copy is complete and accurate (i.e., by viewing/confirming that each has X gigabytes of data)?

Thanks again for your time

Yes once the drives are in an array, you cannot see them individually. They becomes essentially one drive. The RAID controller will make sure that the drives are complete and accurate.

Windows assigns drive letters in order unless you specify them individually, except for C:. C: is your system drive ( the RAID), next is your 1TB drive D:, then the installed Card Reader drives E: and F: . When you plug in an external drive, it would become G:

Also, if the Card Reader drives are not displayed in Computer, it is because it is set to hide empty drives, the default.