Doug,
You know I am (was) an avid FS9 user with every bell and whistle added. My machine has (had) troubles running FSX. It took allot of reading and tweaks to get it to run as best it can. Still, major cities will really take a hit on my machine and when I see a stutter, my entire Sim experience goes down hill. Part of flying the simulator is being able to immerse yourself in the Sim. if everything is running right, you will forget you are sitting in front of a monitor.
When a stutter occurs and gets worse as I am trying to land in FSX, I am removed from my happy simulation.
I was told the machine will handle both programs but several computer folks told me when two similar programs are installed they could work against each other.
False, I have both and have no problems. What the person might have been speaking about is adjustment in hardware for each game like video drivers, etc... One setting might work well in FS9 but not in FSX. Changes in the Sim itself, CFG file etc.. will have no bearing on the other.
Doug what you need to do is basically right here.
http://www.simviation.com/cgi-bin/yabb2/YaBB.pl?num=1183998514/60
If you are familiar with the CFG, this SINGLE page is real nice for tweaking your machine, it is what got FSX flyable for me, along with a few other things. Give it a try. It was posted by Miltestpilot and started by NickN. It will tell you how to adjust the CFG by adding lines and changing things. Then down the screen, Miltest posted some shots of adjustments within the Sim.
It might help you get better results with FSX.
If you miss FS9 and how nice it was to fly, reinstall all of it again and when you want to FLY, load FS9. This way you can tinker with FSX and maybe get it running smooth. If anything at all, you will become familiar with the FSX CFG, how to make changes, and also how different adjustments effect FSX. Remember to keep your FPS text on so you can see how things effect FSX.
Good luck!
Dave