Dont quite get this

So im haveing a hard time breaking 10 FPS with FSX. I turned OFF autogen and have tryed diffrent levels of quality. Sometimes my AA works and sometimes not. I tryed the texture fix and it literally turned my trees upsidedown and srewed with my textures and shows no perfrmance enhancement. My rig is MORE than capeable to run FSX.
AMD Athelon 64 X2 Duel core processor 4200+
2gigs RAM
Nividia Geforce 7900GT 256mb memory
350gig harddrive with a 16 mb buffer
S Series GA-M57SLI-S4 motherboard by Gigabyte technologys
this thing SHOULD be able to run circles around FSX without autogen but its slower then when i was running FS9 off my laptop... wtf.
AMD Athelon 64 X2 Duel core processor 4200+
2gigs RAM
Nividia Geforce 7900GT 256mb memory
350gig harddrive with a 16 mb buffer
S Series GA-M57SLI-S4 motherboard by Gigabyte technologys
this thing SHOULD be able to run circles around FSX without autogen but its slower then when i was running FS9 off my laptop... wtf.