Reinstall Windows 8 ... from within Windows 8
If things go wrong with Windows 8 -- if it becomes riddled with malware or other suspicious code -- you can conveniently restore it to a freshly installed state from within the OS itself. You get two choices: "Refresh your PC" retains your personal files and OS user settings. "Remove everything" performs a complete wipe of all contents on your computer's local drive. To reinstall Windows 8 within the OS, go to the Charms toolbar, select "Settings," "Change PC settings," "General," scroll all the way down, and then choose either "Refresh your PC" or "Remove everything."