XnView Software

I have cached thumbnails on a large external hard drive. However, sometimes, the drive letter changes and XnVeiw needs to scan the whole drive again. In addition to this taking a long time, I now end up with a database that is twice as large. Is there some way to just change the drive letter for the cache (not just add the new drive letter) ?

you need to edit the database file, so not easy.

You can assign a fixed drive letter to your external hard drive or usb sticks.
That is easier to solve the problem.