My External 500Gb hard drive used for back up is shown as full but my 1000Gb 'C' drive on the Computer shows under 100Gb used in the property window. The total of individual files on the hardrive add up to under 200Gb when viewed in Explorer. What is using the capacity of the external drive?
BTW my suggestion re freefilesynch refers only to data. I have my system partitioned to 100 Gog for OS and programmes, and use Acronis True image to do images which work out at about 40 gig each I keep the latest two (non incremental) then ditch the oldest one when I do a new one. I use Freefilesynch in mirror image mode for the data partition. If there is stuff to keep long term I keep it on yet another drive and even on DVD