When you start Disk Defragmenter using any of these ways in Windows 7, nothing may happen except a brief blue circle (hourglass):
Take Ownership of a Registry Key And Assign Full Permissions
Certain areas of the Windows registry cannot be accessed due to the Permissions assigned (or lack thereof) for those keys. For instance, some registry keys are owned by the LocalSystem account, and some are owned by TrustedInstaller. There are legitimate cases where you need to access a registry key to modify or retrieve a setting, … Read more