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HM Nautical Almanac Office: NavPac 3.4 upgrade to NavPac 4

Upgrading from NavPac 3.4 to NavPac 4

To obtain the NavPac 4 upgrade please follow the below process and retain this information for future reference:

We strongly recommend that you begin this process when you can ensure a stable internet connection as the installer is approximately 160MB.

  1. Locate the Serial Number on inside back cover of NavPac and Compact Data 2016-2020.
  2. If the vessel has not registered (subscribed) to NavPac 3.4 via the website, please do so using the NavPac 3.4 Serial Number located in Step 1 and an email address that will be monitored:
  3. Using the NavPac 3.4 Serial Number and the email address used to register NavPac 3.4, proceed to the following website and enter these details:
  4. If entered correctly, you will be presented with a link to download the NavPac 4 Installer file and a NavPac 4 Product Key will appear on screen which will be required in order to install the program on your system.
  5. Please write down the Product Key for future use (an email will also be sent to the Registered Email Address with this information).
  6. Once the NavPac 4 installer has been downloaded, please transfer a copy to a location where you can access it again if needed (e.g. CD).
  7. Start the Installer program and enter the product key when required.
    1. Please Note: some users have reported a profile issue which does not enable other users to access NavPac 4.
    2. Should this occur, uninstall NavPac 4 and then Reinstall it to the following location: C:\NavPac
  8. Go to the following website and register your copy of NavPac 4 using the Registration Email Address and Product Key:
  9. You should now be registered for updates to NavPac 4 and have NavPac 4 installed and working on your system.

Please Note:

If you encounter any issues please contact

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Last modified: Monday, 27 November 2017 at 16:04:27 GMT