Yes. You must get a new Power Supply(unless you want to risk
damaging your system) and for OS< if you want to use your XP or
Vista disc, no problem. W7 is just my suggestion.
I'll do a price break down for you.
CPU + MOBO = $572
RAM = $130+-(somewhere there)
GPU = Which GTX460/560Ti are you going for?
Palit/MSI/Gigabyte/Point of View/ASUS/LEADTEK? For GTX460, the
price hsould be around $200~$300 and 560Ti should be
$300~$400(depending of the manufacturer of the card).
Sound Card = Should be around $100.
HDD = $55+-
Optical drive = $25~$35
Case = (Do you really need such a good case? It cost around $300
which can be used to further upgrade your system like changing it
to a 1TB drive. Such expensive case are usually used for
watercooling. For air cooling, a CoolerMaster Elite 430 is more
than enough to fit in your whole system and you acn even install
fans in it. You can also go and get aftermarket CPU cooler like
CoolerMaster Hyper 212 which cost only $59. Which an aftermarket
cooler, you can overclock your system and get a better performance
overall. Ultimately, it's your choice. Take this with a pinch of
salt :))
Power Supply = $134
Total amount(assuming you're getting a CM Elite 430 case and CM
Hyper212 CPU Cooler and GTX560Ti from MSI) =
$1533+-. If you're going to get the CM HAF 992 casing, it'll cost
around 1.7k.
Remember to bargain with the shopkeeper :)
