I am not sure if i can install osx leopard on virtualbox on window host.
I have the following:
Biostar board
cpu AMD athlon X2 4800+ 2.1 GHz
2GB DDR2 RAM
MDT hdd 600GB
Nvidia gforce ???

I don't know much about hardware.

please help!!
if you need more hardware info. I try to add more.

Virtualbox uses virtualized hardware, you host system is mostly irrelevant. Maybe AMD might be a problem since I have no idea if virtualbox passes cpuid to the VM.