IIt's well known (in these forums anyway) that external hard disks are (far) less reliable than internal ones. So, since data on internal disks needs to be backed up regularly, that's even (far) more necessary for data on external disks. As we say here "you only lose what you don't backup"
Having it done after the fact by some data recovery company, like driversavers.com or ontrack.com or whatever company you trust, is much more expensive than buying a second and third disk to make the occasional backup to. And, moreover, less sure to succeed. So you have to chose between parting from those photos or parting from some money, I'm afraid.
Really starting to panic that I have lost my data...
I have a Buffalo HD-CX500U2 external hard drive. Had it for many years. When connected it would ask for the password (which I still remember).
Suddenly it was not being recognised by the usb port and I tried several, so I thought I was smart and could take the drive out of the case and connect to inside the PC to use. It is recognised in BIOS. However it is no accessible in Windows and shows unallocated. The hard drive itself is a Samsung. I've tried several data recovery programs (demos, trials) and all it seems to retrieve (if anything) are pictures etc that appear to be part of the software installed on the drive for when I need to enter my password. Please help as I have years of family photos and memories I can't part with.