gigabyte motherboard PCIE compatible ?

[bharat.tak8]

hey !
i have a HCL beanstalk modle pc that i bought in 2006.I want to buy a good 512 mb graphic card but dont know whether my motherboard has the correct slot ( PCIe,AGP,etc)
the following are the specifications..

Intel 925/915 Series Motherboard ( gigabyte )
Bus(es) AGP PCI IMB USBi2c/SMBus
MP support 1 CPUu(s)
MP APIC Yes
System BIOS version GBT -42302e31

Please help me