Suddenly turn off and set error and change hard drive and does the same when preparing to read the hard drive is restarted --------------------------------------------------------------- The hard-drive has completely failed, or the hard-drive's "S.M.A.R.T." report has sent a message to Windows that the hard-drive is having problems, and that it is soon to fail. You should copy all your files (to a USB memory-stick, or to a CD-R or DVD-recordable) and purchase a new hard-drive.