To reset a computer that’s using Windows 8 to its original state, perform a refresh via the Update and Recovery utility, or perform a complete reset that removes all personal files and settings. For older versions of Windows, reinstall the operating system by using the installation disc or recovery tool.
In Windows 8 or Windows 8.1, position the mouse pointer in the upper right corner of the screen, move it down, click on Settings, and then click on Change PC Settings. Click on Update and Recovery and then select the Recovery option. Click on the Get Started button in the Refresh Your PC Without Affecting Your Files section and follow the on-screen instructions to complete the process. To perform a complete reset, click on the Get Started button in the Remove Everything and Reinstall Windows section. Both methods require the Windows 8 installation disc or a recovery partition, which most Windows 8 computers feature by default as of 2015.
For computers that use Windows 7, boot the operating system from the Windows 7 installation disc, format the hard drive partition that contains the system files, and follow the installation wizard instructions to reinstall Windows 7. Since this process removes all content from the formatted partition, make sure to back up personal files before proceeding with the reinstallation. If you bought your computer from companies such as Acer, Dell or HP, use the recovery tool and recovery partition that the company provided to reset the computer to factory settings.