Your question is hard for me to understand.
If you mean "I want the UX guidelines for Windows Store applications (not Windows Phone)", they're available on the Microsoft website (Archived Nov. 2012). They're part of a more general overview of the UX of Windows Store apps. Those are the apps that run full-screen.
If you mean "I want the UX guidelines for designing apps for use in the Desktop mode of Windows 8", you should read the Windows UX Interaction Guidelines, paying special attention to the section on Ribbons (which are really emphasised in Windows 8's desktop mode). Those are the apps that run in windows, with the Windows taskbar and your desktop wallpaper visible.