Go to D:\Microsoft Flight Simulator X - Steam Edition\SDK\Core Utilities Kit\SimConnect SDK\LegacyInterfaces\FSX-XPACK or similarly where you have FSX Steam installed. Run the SimConnect.msi installer ...

Superb environment sound file using the Rolls-Royce Trent XWB package, with further updates. Tested in FSX Acceleration (DX10) and FSX Steam Edition (DX9). Not tested in P3D but should work correctly ...