I tried a lot to get the NGX HF4 stable on my system, but from time to time I got blue screens. What I finally found out on my system that the sound drivers were causing issues. Now before starting FSX I turn my system down unplug my speaker cable from the sound card (Speedlink Stage 7.1), unplug my speaker and micro cable from the onboard sound (dedicated to IVAO comms). Then I start the OS and plug all cables in. After that I start FSX. Since then I did not experience any problem anymore ( I hope it will stay this way) You might give it a try, hopefully this will help you too. i7 920 (3.2) Windows7 64 Home, FSX SP2, REX, FSXRealweather, Aivla EFB, a lot of addon sceneries, shade, Saitek Rudder, Yoke, Throttle quadrant.Best regards from EDDMPeter Meinel

You are right! Everyone should remember that a blue screen, technically a "kernel error message" is always due to hardware issues, often related to drivers, and/or software that interacts strictly with the hardware...