Installing Prepar3D on a Secondary Drive: Best Practices for Space and Performance

One of our members recently set up Lockheed Martin’s Prepar3D (P3D) at home to mirror the configuration used in a Redbird simulator at his flight school. 

Like many pilots doing the same, his first concern was storage - particularly once high-resolution scenery packages from developers such as ORBX enter the picture. 

The solution is straightforward: use a fast SSD and install Prepar3D there, rather than on the system drive. Done correctly, there is no downside.

You Are Not Locked to the C: Drive

By default, the P3D installer targets C:\Program Files\Lockheed Martin. This is simply a default - not a requirement. Prepar3D can be installed on a secondary drive (for example, D:\Prepar3D v6) with no loss of functionality. 

This approach preserves space on the system drive and keeps the simulator environment logically separated from the operating system.

Installing the Core Components

Prepar3D installs in three parts: Client, Content, and Scenery. Each component will prompt for an installation location and each defaults to C:. 

When installing to a secondary drive, change the path for all three and ensure they point to the same directory. The installer writes this location to the Windows Registry, allowing add-ons and utilities to locate the simulator automatically.

Files That Remain on the System Drive

Even with P3D installed on D:, certain files will remain on C:. Configuration files such as Prepar3D.cfg reside in the user’s AppData folder, and saved flights are stored under Documents. This behavior is normal and expected.

Add-On Management

Current best practice is to avoid installing add-ons directly into the P3D root folder. 

Instead, place aircraft and scenery in a separate directory - such as D:\P3D_Addons - and use the add-on.xml method. This keeps the simulator stable, simplifies updates, and makes troubleshooting far easier.

Final Thought

Performance depends on drive speed, not drive letter. A modern SSD - whether C: or D: - will provide faster loading times, smoother scenery, and a cleaner, more maintainable setup. 

Prepar3D runs just as reliably on a secondary drive when installed with intent and discipline.

Your thoughts?

Kenneth (Ken) Butterly, Founder