If you're having problems with your PC, you can try to restore, refresh, or reset it. Restoring your PC is a way to undo recent system changes you've made. Refreshing your PC reinstalls Windows and keeps your personal files, settings, and the apps that came with your PC and apps that you installed from Windows Store. Resetting your PC reinstalls Windows but deletes your files, settings, and apps—except for the apps that came with your PC.
If you need to restore your personal files, see How to use File History. If you used Backup and Restore in a previous version of Windows, you can use Windows 7 File Recovery to restore those backups. If you need to restart your PC, see How do I restart (reboot) my PC?