If you want to fix the request could not be performed because of an i/o device error using CMD then you need to follow the below steps: Go to the Start menu & type CMD. Then, right-click on ‘Command Prompt’ > ‘Run as administrator’ > ‘Yes’ to open a Command Prompt as Administrator. Once the new Command Prompt window opens, simply type: chkdsk E: /f /r /x command and replace E with a drive letter.