This video tutorial from Britec09 presents how to backup and restore Window 7 registry.First, press Start button and enter regedit command into Start Search area.Registry editor window will open, click File-Export.This option works on all Windows operating systems.Type file name - registrybackup and click Save. You can save it wherever you want, but in this video it was saved to Desktop.Next step is to reboot to Windows DVD. Insert you Windows DVD and reboot computer.Press any key to boot from DVD. Click Next and then Repair your computer.System Recovery utility will scan for Windows installations. Make sure that Use recovery tools... option is checked.Click Next. Select Command Prompt. Type diskpart and push Enter.Type list volume and push Enter again.Choose C or D volume.Now type Exit. Now type regedit /s d(or C):\Users\Username\Desktop\registrybackup.reg.Push Enter. That should repair your registry if it's corrupted.Type Exit.From System Recovery Options window choose Restart.Make sure you took out DVD or don't press any key while system reboots.Now you will have repaired registry.