Have you experienced Windows 8 freezing or hanging while you’re working on something where you’ve to reboot your system to access Windows again, Microsoft knows about this issue till now there is a workaround to disable dynamic ticking in Windows 8 to fix the freezing, that’s not any more needed as Microsoft yesterday released KB2727113 update which is available for Windows 8 Release Preview and Windows  server 2012 users via Windows Update, since automatic updates already enabled for RP users they’ll be installed automatically, if you want to install this update now, then open Control Panel access Windows Update click on “check for updates” on left-side which shows 2727113 update as important if not already installed on your Computer.

kb2727113 update

Here is what KB2727113 article says

Multimedia or communication activities may cause a computer that is running Windows 8 Release Preview or Windows Server 2012 Release Candidate to stop responding.

On a computer that is running Windows 8 Release Preview or Windows Server 2012 Release Candidate, the system may randomly stop responding (hang) when you work on multimedia or communication activities. This problem may occur during video editing, unified communications, or other multimedia activities.

This problem may occur because of an issue in the interaction between the state-machine driving dynamic tick transitions and the state-machine-driving clock rate changes.

If you’ve followed workaround to fix freezes by disabling dynamic ticking, you’re recommended to enable it back using the following command after applying 2727113 update on your Computer.

bcdedit /set disabledynamictick no