External or internal drive, that is not relevant.
What makes your drive identification a bit more common today is the new trend to use SSD drives. Nothing related with the SS technology, but with the fact that SSD drives are small in capacity and that it is tempting to use them only for the OS and programs and to re-use the old master drive (internally or externally) to keep the photo library. Those SSD are shipped with cloning utilities to move OS and programs (but also catalogs with PSE). When you install the old drive, the organizer will see two different drives with the same Windows serial number even if the letters are now different.
That can be checked by using an sqlite utility and looking at the volume_table table of the 'catalog.pse16db' database. Two different entries in the table will point to the same file location. Some information in this help file for the psedbtool software from John R Ellis.
psedbtool (Photoshop Elements Database Tool)
What can you do if you have two drives with the same serial number? The catalog is wrong, it can't work safely with those two entries for the same location. So, even if you can change the letter drive or the internal serial number from Windows, the catalog will stay wrong.
Can you confirm if the SSD has been 'cloned'?
If so, you may have a catalog copy in both of the drives (catalog location shown in the menu Help >> System Information).
Did you do a full organizer backup before the installation of the SSD drive?
Hi Michel. Thank you, your input has led me to a solution.
I did did indeed have two drives with the same volume serial number one of which holds the photo library (D:). The other drive (F:) held nothing of consequence so I reformatted it. That gave it a new volume serial number. Elements organiser now seems to work fine again and expects the photos to be on the D: drive rather than F:
I did try the psedbtool but it does not seem to work with the latest version of PSE. The notes by John R Ellis were helpful but they appear to be somewhat dated so anyone else finding this thread should bear that in mind.
It did occur to me that PSE should warn the user of duplicate serial numbers during installation, just a suggestion for Adobe.
Thank you once again
Carole