i am having windows 8.1 pro update1 on my desktop. recently i started getting a lot of garbled display on the pages. i ran malwarebytes, and found no virus. ran sfc /scannow and did not find defects. booted with windows 8 media (both dvd and later usb pen drive), chose repair drive and attempted to refresh but always getting the message "the drive where windows is installed is locked. unlock the drive and try again. i made more than a dozen attempts but got the same message, even when i tried to refresh from within windows, getting the same message
summary of problems
1.windows display on opened documents is frequently getting garbled.
windows refresh tells that the boot drive is locked.
can some experienced person guide me without taking me on a tour of the globe?