ozturk ozer - 2026-09-25

External HDD – Correct password but volume won't mount (MountVolume:9553 / 4549)

Hello,

I need some help recovering access to a VeraCrypt-encrypted external HDD.

The HDD was encrypted with VeraCrypt on another Windows computer some time ago. I am now connecting the same physical HDD to a different Windows PC using a USB HDD enclosure.

VeraCrypt detects the disk/partition normally, but I cannot mount the volume.

I am confident that I know the correct password and, as far as I remember, the password has never been changed.

When I try to mount the volume, VeraCrypt reports:

Operation failed due to one or more of the following:

Incorrect password

Incorrect Volume PIM

Incorrect PRF (hash)

Not a valid volume

Source: MountVolume:9553

On another attempt, I also received:

Source: MountVolume:4549

There is one detail from the original encryption process that may be important.

As far as we remember, the actual encryption process reached the end. However, VeraCrypt was performing some kind of finalization/closing operation at the very end of the process, and it is possible that the program or computer was closed during that final stage.

I am not saying that encryption was interrupted halfway through while the disk was still being encrypted. My concern is specifically that the encryption itself may have completed, but the finalization/closing stage immediately afterward may have been interrupted.

Unfortunately, I cannot remember exactly what VeraCrypt was doing at that final point.

Could interruption at this stage cause the volume header or other VeraCrypt metadata to remain in an incomplete/inconsistent state and later result in the password/PIM/PRF/not-valid-volume error?

I would also like to rule out other possibilities, such as:

Volume header corruption

Different PIM or PRF/hash settings

Selecting the partition vs. the entire physical device incorrectly

VeraCrypt version compatibility

An older VeraCrypt/TrueCrypt format or algorithm

The USB HDD enclosure presenting the drive differently from the original SATA connection

Another mount option that may have been used when the volume was created

The data on this HDD is important, so I do not want to perform any operation that writes to or modifies the encrypted disk until I understand the problem.

What would be the safest diagnostic procedure in this situation?

In particular, is there a safe way to determine whether the primary/backup volume headers are valid, or whether the finalization stage of the original encryption was not completed, without modifying the disk?

If necessary, I can provide the VeraCrypt version I am currently using, Windows version, HDD/partition layout, and any other technical information needed.

Thank you for your help.