Radeon HD 2400 xt....upgrade?

[RenoFlyer]

Hey everyone,

I've been searching and researching the forums, and am suffering information overload. Can you guys give me some advice?

I just bought a gateway system that has a AMD Phenom 9500 Quad Core, 3 Gigs of RAM, 1 TB HDD, and a Radeon HD 2400 xt 256 mb. Windows Vista Home.

My old system was an AMD Athlon 1.7 o/c to 1.8, 2 Gigs of RAM, and a Geforce 6600 128 mb(if I remember correctly) graphics card. Windows XP Pro.

I happily installed FSX & Acceleration, anxious to check out my newfound flying abilities....then the problems started.
At first, I would go into Free Flight, and it wouldn't load. It would bring up the cockpit, then instantly go black, bring up the cockpit, black,.....until I hit escape and exited flight.
I selected the DX10 Preview button, and tried again. It loaded, but is choppy as hades. I've turned down everything, but it's still choppy. I had higher settings on my old system and it ran beautifully.

So, needless to say, I'm searching for answers. Is it the HD 2400? Is there something else I need to do with Windows Vista? Any help you guys can offer is greatly appreciated. My girlfriend and I are both taking flying lessons right now, and she could use the simulator. I was raised in airplanes, so my instructor told me I was ready to solo after 3.7 hours (3 lessons).  ;D

Thanks for any help guys!

[Wii]

Could be the drivers. But first, try right clicking on the FSX.exe and clicking Run As Admin and see if that helps first.

[RenoFlyer]

Would it even start if it wasn't in admin mode?