Changer carte graphique?

Bonjour,

j'aimerais changer de cg par une gtx et j'aurais voulu savoir si elle serait compatible avec mon pc,
voici les caracteristiques de mon pc:

Operating :
system Genuine Windows Vista® Home Premium 64-bit

Processor :
Intel® Core™2 Quad processor Q9300
Intel® G33 express chipset

Memory :
4 GB DDR2-SDRAM
4 DIMM sockets

Storage :
750 GB SATA 3G Hard Disk Drive (7200 rpm) up to 12 GB partition for system recovery
HP Personal Media Drive and HP Pocket Media Drive sold separately
DVD writer SATA DVD RAM and Double Layer supporting LightScribe technology
Create silkscreen-quality disc labels direct from your PC with LightScribe: Just burn, flip, burn.
15in1 memory card reader

Communication :
Ethernet 10/100/1000BT integrated network interface
Wireless LAN 802.11 b/g

Video :
NVIDIA® GeForce™ 9600 GS with PureVideo® HD technology (DVI/VGA port, HDMI port, TV-out)
768 MB dedicated memory, up to 2559 MB total available graphics memory as allocated by Windows Vista®

Sound :
Intel® High Definition Audio 7.1
2 front audio ports, 6 rear analog audio ports & 2 rear digital audio ports

Included accessories :
Wireless keyboard and optical mouse
HP Vista Media Center Remote Control

Optional accessories LCD Monitors (buy separately): HP w1907v 19" Wide
Flat Panel Monitor, HP w2007v 20.1" Wide Flat Panel Monitor, HP w2216 21.6" Wide Flat Panel Monitor, HP w2228h 22" Wide Flat Panel Monitor,
HP w2448hc 24" Wide Flat Panel Monitor

Ports & Expandability :
2 external optical drive bays, 2 internal HDD bays, 1 Pocket Media Drive bay, 1 Personal media Drive bay ;
Landing pad for USB & 1394 devices
1 PCI-Express 16x
1 PCI (1 free) and 2 PCI-Express 1x (2 free)
6 USB 2.0 ports (2 in front)
2 FireWire®-IEEE-1394 ports (1 in front)

merci d'avance pour vos réponses ça m'aiderait bien