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)