For long-winded reasons I'd rather not explain nor defend, my partner uses Dropbox for a large set of important files (~70G), which are stored on a removable drive. She is also a Windows user. Recently, by introducing a few new drives, I inadvertently changed the drive letter that is assigned to her portable device, which stopped Dropbox from working. Solving this properly is rather finicky so I thought I'd write down what I did.
The end goal is to try and ensure that the portable drive always gets the same
drive letter and that Dropbox is configured to use that drive letter, but
before I can get that far I need to get Dropbox syncing again. It used to be
F:, and I opted for
U: going forward.
Luckily the extra letters I'd introduced were all partitions on a separate
hard drive from the OS, so I powered the machine down, unplugged the extra
hard drive and booted back up. This freed up the stolen drive letters, but
the portable drive did not re-inherit them. Running
regedit as an
administrative user and renaming keys in
moved the USB drive back to the correct letter, but I suspected the extra
hard drive would take precedence when it was back, so this was only an
With the portable drive back on
F:, the Dropbox client was happy once again.
However I needed to reconfigure the Dropbox client to use a different letter.
I wasn't happy with the idea of altering the Dropbox client's configuration
database under its feet, so I had to do everything "by the book". Luckily,
the client supports the notion of moving your Dropbox folder. Combined with
subst command (run as the local user rather than as an
admin this time), I was able to clone the
F: drive to a virtual
and then ask Dropbox to move the folder.
subst U: F:\
This was pretty awkward.
U:\Dropbox are in fact the same
folder, so I needed to ask Dropbox to move it from
F: to something other
U:. I opted for
U:\tmp. The move took a long time (~2 hours).
The proper solution is to try and get a stable drive letter for her device. This can be achieved using a tool called 'USB Drive letter Manager', or USBDLM. USBDLM is free for educational use, and my partner is a teacher, which is lucky.
Once that's all sorted, reboot, insert portable device, ensure it's on the
right drive letter, and move the Dropbox folder back down to
U:. This time
the move was near instantaneous.