FSX won't start

Every time I click the shortcut (I've tried the app in the main folder, too) I just get the FSX splash screen. I then let it sit, and sit, and sit, but it never loads! It will just show me a splash screen for hours.
This happened before, after I first installed FSX. It would let me open it up and fly like 3-5 times, then refused to ever start up again! So I ran repair, uninstall, and reinstall. Then it let me fly in it about 3-5 times, but refused to ever start up again! It ran fine before
Could I have done something wrong? Please help!
System Specs:
HP Pavilion with Vista Home Premium 6.0 - 32-bit
AMD Athon 64 X2 Duel Core Processor 4400+ (2 CPU) ; 2.30 GHz
2046 megabytes RAM
320 GB Hard Drive
NVIDIA GeForce 8600 GTS Video Card (1008 MB memory)
This happened before, after I first installed FSX. It would let me open it up and fly like 3-5 times, then refused to ever start up again! So I ran repair, uninstall, and reinstall. Then it let me fly in it about 3-5 times, but refused to ever start up again! It ran fine before

System Specs:
HP Pavilion with Vista Home Premium 6.0 - 32-bit
AMD Athon 64 X2 Duel Core Processor 4400+ (2 CPU) ; 2.30 GHz
2046 megabytes RAM
320 GB Hard Drive
NVIDIA GeForce 8600 GTS Video Card (1008 MB memory)