Recovery drive HDD drive letters

Question

I need to understand how drive letters are allocated. Particularly when running a Windows 10 recovery drive system. There does not seem to be a sencible way of predicting what drive on the live system will be when using the recovery drive system. Where can I get more detail information about the drive letter allocation within the Recovery Drive system?

Answer 1

Hi @Alan Cameron

The OS has dynamic and manual ways of assigning drive letters plus some special predefined allocations.

Upon installation the Windows OS will assign the drive letter C: for the OS drive and if your computer has a floppy drive, the A: volume letter will be assigned by default.

Any additional drive added into the system that has a compatible file system detected, the OS will allocate the next available drive letter. So if for example you have "C" allocated to the system, "D" to your data drive, and you plug a USB, the next available letter will be "E".

In the WinRE the X: drive letter is a ram-disk, a volume that resides in-memory, where the entire pre-installation environment runs. As for the volumes detected by the WinRE on you physical disks they will shift to their next letter.

In the previous example you C drive will become D and D will become E and so on.

Regards
IP.

Answer 2

@Alan Cameron
Hi,

Use Diskpart to Find & Select your Recovery Partition
then type
Code:
set id="de94bba4-06d1-4d40-a16a-bfd50179d6ac"
gpt attributes=0x8000000000000001

For your reference:
https://learn.microsoft.com/en-us/troubleshoot/windows-server/backup-and-storage/restore-system-boot-drive-letter

Hope above information can help you.

============================================

If the Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 3

@Jenny Feng .
Thank you Jenny for responding to my question.
I have read the quoted article but found it difficult to understand to which part you were referring.
I have attached two files diskpart1.txt and diskpart2.txt which demonstrate my confusion.
Diskpart1.txt is the display of the volumes and disks which appear when I boot my machine from the recovery drive and Diskpart2.txt is the same display when diskpart is run from a cmd prompt.
If you look closely you will see the different letters that are used for the 4TB drive in the two different files.
Is this what you expect to see when running the OS from the recovery drive?