Per Great Planes Software Support:
Here are the complete instructions for downloading/installing Add Ons Volumes 1 and 2 content in to RealFlight G4:
RealFlight Add-Ons 1 & 2 have been repackaged for RealFlight G4. Even better, they are now available as free downloads to all RealFlight G4 owners! Numerous technical issues prevented the original Add-Ons disks from working with G4, but because we want G4 users to have access to this content, we're giving it away. In cases where a Volume 1 or 2 aircraft was already offered with RealFlight G4 (e.g. the Piper Cub), that aircraft will not appear in the repackaged Add-Ons. All of the Add-Ons content is otherwise unmodified.
The repackaged Add-Ons volumes are ONLY compatible with G4 version 4.00.051 or later. If you have not yet updated your G4 installation to version 4.00.051, the automated updating process can be found on the G4 Launcher window (select Additional Options -> Registration/Updates).
INSTRUCTIONS
Here is a link you can use to download the Add-Ons 1 zipped folder:
http://www.knifeedge.com/downloads/RFAOV1_G4.zip (temporary link to Add-On 1, use
http://www.realflight.com/free-g4-add-ons.html for 3-5 when available)
Here is a link you can use to download the Add-Ons 2 zipped folder:
http://www.knifeedge.com/downloads/RFAOV2_G4.zip (temporary link to Add-On 1, use
http://www.realflight.com/free-g4-add-ons.html for 3-5 when available)
For each file downloaded above:
1. Unzip the file. If you have Windows XP or Vista, you can just double-click it.
2. Extract the .zip file's contents to C:\Program Files\RealFlightG4\Data.
3. Run RealFlight G4 and the Add-Ons content should be available in the aircraft and airport selection dialogs.
PLEASE NOTE: DO NOT attempt to use the Add Ons CD ROMs to install Volumes 1 and/or 2 in to RealFlight G4. These specially prepared zipped folders and instructions are the ONLY way to install Volumes 1 and 2 in to G4. Add-Ons 3, 4, and 5 will also be re-packaged for G4 and released for free when they are ready. These files will NOT work with any other version of RealFlight. This content is released "as-is".
For more information, here is a link to the original announcement on KnifeEdge.com:
http://www.knifeedge.com/forums/show...207#post113207