A teacher accidently started to synchronise with our intranet. He got rid of everything he could find that had been downloaded to his laptop, but the disk is showing under 10Gb free. He is sure there should be more. I added up all the space used by all files and directories (including the pagefile, hiberfil.sys and hidden recyclers) and there is definitely 30Gb unaccounted for. I am stumped! Any and all suggestions would be gratefully received.