Welcome to these user forums.

Normally the System reserved partition should not have a drive letter and be a hidden partition, so you shouldn't have been seeing either F: or D: for that partition.

If you have a full disk drive backup image that you are looking to recover from, then you should use the option to recover the whole disk and not get into needing to select individual partitions.

See the ATIH 2016 User Guide: Recovering partitions and disks where it states:

To recover partitions or disks:

1. Start Acronis True Image.
2. If you want to recover your data from Acronis Cloud, make sure that you are signed in to your Acronis account.
3. In the Backup section, select the backup which contains the partitions or disks you want to recover, and then click Recover disks.
4. In the Backup version list, select the backup version you want to recover by its backup date and time.
5. Select the disks to recover.

   If you need to recover separate partitions, click Recover specific partitions, and then select the partitions to recover.

6. In the recovery destination field below the partition name, select the destination partition. Unsuitable partitions are marked by red lettering. Note that all data on the destination partition will be lost because it is replaced by the recovered data and file system.

   To recover to the original partition, at least 5 % of the partition space must be free. Otherwise, the Recover now button will be unavailable.

7. [optional step] To set up additional parameters for the disk recovery process, click Options.
8. After you finish with your selections, click Recover now to start recovery.

I appreciate you coming back so promptly, Steve.

I repeated the steps, noting your guidance, but got  the same outcome, so maybe I missed something or maybe there's oddity somewhere in my system.

I therefore decided to execute the recovery to see what would happen, and I'm pleased to be able to say that it worked just fine and that the main system reserved partitions ended up labelled as C: and F:, as they had been before the failed install.

A bit of a mystery then, but a perfect outcome. Many thanks.

Thanks for the feedback, glad the outcome was successful, even if there is still an air of mystery here!

Perhaps the drive letters you were seeing were the ones listed in ACronis recovery - which uses Linux? It's not uncommon for the reocvery media to list all paritions with drive letters and letters that don't match what is listed in your Windows OS since each OS has it's own configuration.

1519: Acronis Bootable Media Displays Wrong Drive Letters

Symptoms

1. You boot from Acronis Bootable Rescue Media (full version);
2. The partition and drive letters are different from the ones displayed in Windows.

Cause

The full version of Acronis Bootable Rescue Media uses Linux environment. This results in the default Linux letter assignment rules, which may be different from the ones in Windows.

Solution

Try identifying the drive or partition you need by size or label.

Got that, thanks

I also saw different drive letters and it scared me :-(
Surely there should be a message explaining why the drive letters appear to have been changed?

JohnF,

Unfortunately no, because it varies from system to system and how the bios reports them to the booted OS. One one computer, it might show up correctly, but another system not. There's no way for the new Linux bootable environment to know what the Windows OS had the drives mapped/mounted as.

Even Windows can be limited in the capacity. For instance, your OS is always C:, but if I recover the OS to a second hard drive and boot the original OS, it will remain C, but Windows will give the recovered OS partition a different drive letter (the next available), because C: is already in use. However, if you then boot to the newly recovered hard drive, the OS will show up as C:. Clear as mud?

When booted from the Linux based Rescue Media there is an immediate message shown on the Acronis first screen to state clearly that drive letters may appear differently than those shown in Windows.
This can be seen even on earlier versions of ATIH such as 2014 as per the screen shot attached below which I took yesterday when booted from that media.

Thank you Steve. Somehow, in my anguish, I failed to see that message.