Esh535920 is correct with: "Do NOT install SP2 and then Acceleration! If you install Acceleration with SP2 you WILL have issues. Only install 1 or the other. Microsoft even says not to install both." It's been a long time since I installed Acceleration, and I did install it over SP1 without any issues at all, but I wonder if SP 1 is even required to install newer versions of "Acceleration". One would think not, if both FSX and Acceleration are packaged together, as in the case of FSX Gold Edition. Does anyone know for sure?
I agree with Steven about your system being more than capable of running FSX, and, also like Steven, my first thought was heat, even though it doesn't sound like you ran the sim long enough for heat to be an issue. Do you know how to monitor your processor and video card temps? If not, try CPUID Hardware Monitor. Here is the link: http://www.cpuid.com/ Make sure you get the 64 bit version.
If you are going to reinstall, give FSX a try right after installation and before installing Acceleration or any service packs. Instead of trying a "tutorial", just load the default "Free Flight" to see if that works.
Don't let it frustrate you! I'm sure it's something easily fixed, once we figure it out. Please post your temps and let us know how you make out.
See ya, Milt
If it ain't broke..., fix it any damn way!!!