Re: Video Card Upgrade For My Inexpensive HP Presario...???
If you want a GTX 285 you're gonna need a much bigger PSU - 700W + I'd say, you're also going to have to make sure it'll fit in your case. I have a GTS 450 and a 650W PSU and it runs well, not sure how it would do on a 450W PSU though, but my recommendation to you for FSX would be to get a bigger PSU, 700W or higher and a GTX 560, or the GTX 285 if it's cheaper for you.
My Custom-Built PC
Core i5 760 2.8GHz, 8GB DDR3 Dual-Channel, 2TB HDD, 120GB Crucial M4 SSD, EVGA GeForce GTS 450 SC, Foxconn H55M-S Motherboard, NZXT Lexa S Case, CIT 650W Neon PSU, Windows 7 Ultimate x64 SP1