By disabling the Windows prefetch and superfetch features, you can avoid generating prefetch files and the overhead associated with prefetch and superfetch operations. This action can reduce the growth of linked-clone machines and minimize IOPS on full virtual machines and linked clones.

About this task

To disable the prefetch and superfetch features, you must edit a Windows registry key and disable the Prefetch service on the virtual machine.


See the Microsoft TechNet Web site for information on how to use the Windows Registry Editor on Windows 7 and Windows 8.


  1. Start the Windows Registry Editor on the local Windows 7 or Windows 8 virtual machine.
  2. Navigate to the registry key called PrefetchParameters.

    The registry key is located in the following path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters.

  3. Set the EnablePrefetcher and EnableSuperfetch values to 0.
  4. Click Start > Control Panel > System and Security > Administrative Tools.
  5. Select Services and click Open.
  6. Double-click the Superfetch service.
  7. In the Superfetch Properties (Local Computer) dialog, click Stop.
  8. In the Startup type menu, select Disabled.
  9. Click OK.