How do I deactivate a Prepar3D licence for a new PC?

To deactivate a Prepar3D licence before moving to a new PC, keep the old computer online and uninstall Prepar3D through Windows. When the uninstaller asks whether to deactivate the licence, choose yes. Do not simply delete its folders: that removes files without reliably returning the activation for use on the replacement PC.

How to deactivate the Prepar3D licence correctly

1. Back up your settings and add-ons. Deactivation does not transfer aircraft, scenery, controls or configuration files. Our backup-first method for changing Prepar3D without breaking add-ons covers the same precautions needed before a PC move.
2. Collect your licence information. Keep the activation key, purchase details and installer for the exact Prepar3D major version and edition you own. Deactivating one version does not upgrade its licence to another.
3. Keep the old PC connected. Close Prepar3D and related utilities, then make sure the computer has a working internet connection so the licensing system can process the deactivation.
4. Open the Windows application manager. Use Installed apps, Apps and features, or Programs and Features, depending on the Windows release.
5. Uninstall the correct Prepar3D entry. Its name varies by version and licence edition. Select the main Prepar3D or Client entry, not Content, Scenery, SDK or an individual add-on.
6. Confirm deactivation. When the uninstaller asks whether the licence should be deactivated, choose yes and allow the process to finish. Do not disconnect the network, restart or power off the computer during this stage.
7. Install Prepar3D on the replacement PC. Use the same licensed version and edition, activate it with your existing details, and verify that the unmodified simulator starts before reinstalling add-ons. Follow our Prepar3D installation steps for a new PC if needed.

After deactivation finishes, you may remove any remaining Content, Scenery and SDK components from the old computer. If you were only updating the Prepar3D Client on the same PC, you would normally decline deactivation; moving to another computer is the case where it should be accepted.

What should I back up before uninstalling Prepar3D?

Back up user-created files and installation records before touching the old installation. Useful locations commonly include the Prepar3D folders under Documents, %APPDATA%\Lockheed Martin\Prepar3D vX and %PROGRAMDATA%\Lockheed Martin\Prepar3D vX, where vX represents your installed major version.

• Control assignments, saved flights and camera settings
• add-on.xml packages and scenery configuration
• Aircraft, scenery and utility installers
• Serial numbers and activation details for paid add-ons
• Custom textures, effects, gauges and configuration edits

Do not copy the entire old Prepar3D installation folder over the new one. That misses required Windows registrations and dependencies while carrying across obsolete configuration. Install the base simulator cleanly, test it, then restore add-ons and settings selectively.

What if Prepar3D does not show a deactivation prompt?

A missing prompt usually means the wrong component was selected or the licensing process could not communicate successfully.

• Check that you removed the main Prepar3D or Client component rather than only Content or Scenery.
• Reconnect the PC to the internet and make sure security software is not blocking the uninstaller's network access.
• If the installation is damaged, run the matching Prepar3D installer and use its repair or maintenance option before attempting the uninstall again.
• Do not erase the drive until you know the deactivation has completed.

If the software has already been removed without a prompt, retain the exact error message and your purchase information. The licence issuer's support team must resolve an activation that remains assigned to inaccessible hardware. If you need help separating a local installation problem from a licensing problem, you can contact our simulation support team, although we cannot reset publisher-issued licences.

What if the old PC has failed or been wiped?

You cannot perform a normal local deactivation after the old operating system is gone. Install the correct Prepar3D version on the new PC and attempt activation once; if it is rejected because the previous machine remains registered, contact the licence issuer with the key, purchase details and complete error message.

A disk clone does not avoid this problem. A new motherboard or substantially changed hardware can be recognised as another computer, so deactivate Prepar3D before cloning, replacing major components or reinstalling Windows whenever the old system is still usable.

Do Prepar3D add-ons need separate deactivation?

Prepar3D's deactivation prompt affects only the simulator licence. Commercial aircraft, scenery and utilities may use their own machine-based activation slots, so deactivate those through their supplied managers before removing Prepar3D when that option exists.

Uninstalling the Prepar3D Client may leave add-on folders and user configuration behind, but those remaining files do not prove that either the simulator or an add-on licence was deactivated successfully.