Sorry Nostra, looking again I can see why my e-mail was misconstrued.
The external hard drive is third in line for the back ups,
I back up most nights all my film data to an SD card inserted in the computer, then the next back up is to a 16GB USB drive, and thirdly once every month or so I back up to a large external hard drive.
The PVDB back up on the SD card and USB stick are up to date, if anything happens it is a simple transfer, but this time PVDB did not like either of these files and even when C&P'ing them onto the C Drive would not work, I haven't the faintest idea why?, (I have recalled that I have had problems restoring from USB keys and SD cards many years ago).
I did manage to use the large external hard drive, sadly the data was about four weeks old, so I spent the whole of the day re-installing all the lost data back onto the computer and now I am almost up to date.