Got it working on DELL XPS 9000 that I purchased in 2009. Had to replace the Radeon HD4870 video card with a Radeon HD6450 to get the video to work properly. This was due to Microsoft Windows 10 not supporting the HD4870. The other issue was by Creative Labs X-Fi Titanium Sound Blaster. Creative labs just released the drives for Microsoft Windows 10.

Initially Realflight 7.5 ran like a dog due to slow graphic frame rates (Less than 20 Frames / Second). After I reset the defaults on Realflight 7.5, I was able to increase the frame rate to 40-80 frames / second

Realflight 7.5
Airport: Flight School
Airplane: B-25 Mitchell
Graphic Quality: Medium
Resolution: 1920 x 1200 Medium 16 Bit
Full Screen Mode: No

Computer: DELL XPS 9000
CPU: INTEL Corei7 2.93Ghz
Memory: 24GB RAM
Operating System: Microsoft Windows 10 Pro (64-Bit)

Realfligh 7.5 does not seem as smooth running under Windows 10 (64 Bit) as it did on 7 (64-Bit).