unlike Windows 7, there's no "Desktop Window Manager Session Manager" service in services.msc in Windows 8. if you delete C:\Windows\System32\dwm.exe under explorer7, you can enter desktop after reboot, but black screen after logoff and logon ie you lose the ability to logoff I don't think it's a big problem though. under explorer8, unable to enter desktop after reboot, black screen instead. it's also a black screen after switch explorer7 to explorer8. ie dwm.exe is necessary for explorer8.