Ok,
mike-wsm, it is on the to-do list, the cameras all operate on expensive flash storage, but I'm getting round to the edit suite! Curiously enough, after posting this morning I once again went through the defrag routines, etc, much quieter now. About to re-do chk disk etc. I defrag once a month but maybees my data input (large) recently has given it a wobbler.
Bushfiva, lost a 1tb external drive completely 2 years ago which is why I now panic a bit...still have the bits, but it's £700 to restore (2 x 500gb)

Thanks for all the encouragement folks..