Disable defragmentation at start up (Boot)

April 2018


Windows Vista and Seven defragment system files every time you boot your PC. If you often defragment your hard drives, this automatic feature is unnecessary

and it slows down the launch of Windows. To disable it, you must modify the Windows registry.


  • Open the Registry
  • Start/All programs/Accessories/Run
  • Type the command regedit
  • The Registry Editor opens in a new Window.
  • Expand the key: HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Dfrg>BootOptimizeFunction.
  • Right-click on the keyword "Enable" and click edit
  • In the Value data field type, N
  • Confirm by OK
  • Right-click on the keyword "Optimizecomplete" and click edit.
  • In the Value Data field, replace Yes by No. (case sensitive)
  • Confirm by OK
  • Close the Registry Editor. Changes will be effective upon restarting Windows.
Published by netty5. Latest update on July 21, 2010 at 08:10 AM by netty5.
This document, titled "Disable defragmentation at start up (Boot)," is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM (https://ccm.net/).
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