Rob is well qualified and widely experienced in computing since graduating MSc Information Technology in 1986. Had a strange one last week. A Windows 8 laptop belonging to a pre-teen girl in Dunblane seemed unable to run most programs. Chrome, Minecraft, The Sims all failed to start, with no error messages. Malware scans came up with very little, very unusual for that demographic in my experience, eliminating what was found made no difference to the behaviour, and I couldn't get into drive properties to run chkdsk. Probably because I'd been using shift-restart so much to get into safe mode it occurred to me I could get a command prompt under the advanced options and run chkdsk from there, so that's what I did. Lo and behold, loads of errors came up using /f so despite it being a relatively new machine I ran it again using /r. No bad sectors, so I've no idea what caused the problem, but chkdsk fixed it, so happy lassie, happy parents, happy me.