In earlier Windowses, if you pressed F8 at boot time, you’d go to a special “Safe Mode,” which was very useful for repairing a damaged install that otherwise wouldn’t boot. Safe Mode still exists in Windows 8, but it’s disabled by default. To enable it:

Step 1. Run a Command Prompt as Administrator.

Step 2.Type:

bcdedit /set {default} bootmenupolicy legacy

That’s it! Pressing F8 at boot should now bring up the traditional Safe Mode menu.