Again, thank you for those inputs. The various methods of indicating disk contents all showed a nearly full 1.5 Tb disk but only 110Gb specifically accountable. Decided that the 'simplicate and add lightness' dictum was best,, so did a transfer of the 110G to another disk, formatted the 1.5Tb and transferred the 110Gb back again. So far, (fingers tightly crossed) it appears to be back to normal. I appreciate that I haven't found the 'problem' but 0s and1s technology makes my head hurt!!