Pentium D 3.00Ghz (Dual Core)
nVidia GeForce 670XL
250MB hard drive space
Will this be able to run Direct X 10 and also will it be able to run a 64BIT Operating System, like Windows Vista?
LOL, most likely not.
Vista will take 1 gig of ram for itself.
Your card isn't optimized for DirectX 10 which is in Vista and will be used to enhance FSX.
You need at least 1 more gig, 2 would be great and when the DirectX cards come out you'll have to replace yours.
The CPU is sufficient.