Microsoft's intention to optimize the upcoming Windows 8 operating system for mobile devices like netbooks or tablets has the consequence that the Redmond company has to optimize the operating system's power consumption. Laptop users with optical disk drives may benefit from the operating system's support of a feature called Zero-Power Optical Disk Drive (Zero Power ODD) which basically can reduce the power consumption of optical drives to zero in the operating system to save energy when the drives are not in use.
Zero-Power Optical Disc Drive is part of the SATA 6GB/s specification (to be precise SATA revision 3.1). To support the new power saving feature of the latest SATA revision, the computer system and operating system need to support it. If your computer does not support Sata 6GB/s connections you cannot make use of the power saving feature.
Zero-Power ODD is enabled by default in the Windows 8 operating system. Windows 8 will recognize compatible drives automatically and use the feature to save power. This basically means that the optical drive does not need power at all if it is idle.
While unlikely you may encounter situations where the new feature acts up, or where you under no circumstances want to save power using that feature.
Windows 8 comes with an option to disable Zero-Power ODD. In the developer preview edition you need to change the value of a Registry key for that.
Open the Windows Registry editor first. You need to bring up the run box with the shortcut Windows-r, type in regedit and hit enter. This displays a prompt for elevation which you need to accept.
Navigate to the Registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\cdrom\parameters\ and locate the parameter ZeroPowerODDenabled on the right side. It is likely that you only see the parameter if your computer supports the feature.
Double-click the value and change it to 0. You then need to restart your computer before the changes become active. You can at any time enable the feature again by repeating the steps. The only difference is that you need to set the value to 1 instead of 0 to enable it. (via)