When I started FSX program, I received error code 1-80004005, product activation error. I have been reading the MS support forums and articles along with dozens of FSX support sites with no luck. I am apprehensive of altering or changing my registry since it is a new PC. I tried repairing Acceleration, uninstalling and reinstalling as Administrator, and even used a second FSX and Acceleration program that I purchased as a backup. It appears that FSC Acceleration cannot be loaded on a new PC on Windows 10. Microsoft Flight Simulator X Service Pack 2 (SP2) / Acceleration (XPack) / Steam Edition Lockheed Martin Prepar3D v2.5 / v3.X (up to v3.8) You will need NVidia drivers 376.33 or older, if you are using Prepar3D v3.8 due to a limitation in the Prepar3D graphics code causing DXGI errors. I have another PC that is only 13 months old with Windows 10 and FSX and Acceleration installed fine with no problems. #FSX ACCELERATION ACTIVATION PHONE NUMBERS DRIVERS# Please can someone help me with a fix for this problem, I have been using MS Flight Simulator since 1983 and it is the only game I play every day. #FSX ACCELERATION ACTIVATION PHONE NUMBERS SIMULATOR# #FSX ACCELERATION ACTIVATION PHONE NUMBERS SIMULATOR#.#FSX ACCELERATION ACTIVATION PHONE NUMBERS DRIVERS#.