How do I disable the Windows built-in defragger?

FAQ Download And Install - How do I disable the Windows built-in defragger?

Windows 2000 & 2003:

The built-in defragger is not started automatically.

Windows XP:

1. Download the free  Tweak UI utility from Microsoft.
2. Click on "General" and untick the "Optimise hard disk when idle" box.

Windows Vista:

1. Start -> All Programs -> Accessories -> System Tools -> Disk Defragmenter
2. Untick the "Run on a schedule (recommended)" box.

Windows 7:

1. Klick on Start, type "services.msc" in the search box.
2. Search for the "Defragmentation" service and disable it.

The following registry settings have something to do with the build-in defragmenter. There is no official Microsoft documentation for these settings, so any information you may find on the internet regarding these settings is guesswork, and I will not add to that. My advise is not to play with these settings, you are on your own here.

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\BootOptimizeFunction\Enable
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\OptimalLayout\EnableAutoLayout
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnablePrefetcher

See also:

 Frequently Asked Questions