Howtogeek shows you how to Enable, Use, and Disable Safe Mode in Windows 8

If you've installed the Windows 8 Developer Preview and have run into some problems (after all, it?s pre-beta software), you may want to boot into Safe Mode to try and fix the problems.
By default, Windows 8 does not enable Safe Mode. You have to manually enable it. This article shows you how to enable Safe Mode, boot into it, and then disable it.
To enable Safe Mode, you must open the Command Prompt window. There are a few ways you can do this. You can use the Metro UI, the Windows 7 Start menu, or Windows Explorer to search for the cmd.exe command.
To use the Metro UI, open the Desktop from the Metro Start screen. Move the mouse over the Start icon and then select Search from the Start menu to open the Search pane.

  Enable, Use, and Disable Safe Mode in Windows 8