Disable defragmentation at start up (Boot)


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.
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