How to Switch from IDE to AHCI without repairing/reinstalling Windows

A few weeks ago I installed an SSD drive in my home PC. For some reason up until tonight I never checked what the Sata mode was set to in the bios. It was set to IDE. Usually when changing the storage mode in the bios requires a reformat as windows will no longer boot. So I looked around the internet and found some really great instruction to switch from IDE to AHCI without having to repair or reinstall windows. Thought I might share it.

You start with step 1 while you are still in windows in IDE mode.

  1. Run the Registry Editor (regedit.exe)
  2. Navigate to Registry Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
  3. Set the “Start” value to 0 (zero)
  4. Navigate to Registry Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Pciide
  5. Set the “Start” value to 0 (zero)
  6. Shut down
  7. Start up again, but before Windows boots go into the BIOS configuration screens and change the disk mode to “AHCI”. Save the new BIOS configuration and restart so that Windows boots.

When Windows starts, it will detect the change, load new disk drivers, and do one more reboot to start up with them. A quick little post, more to come.

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