.cso

i have a psp (i dont know the model).i have downloaded a game (gta liberty city stories).now what to do so that i can play the game in my psp (when opened, it has files like a-gtalcs, a-gtalcs.002).I also have a god of war demo in .cso format. how to play that??? Thanx in advance! please guys...

hello ppl... i downloadeed a game .. and after unzipping the folder i got a file with a " .cso " extension.... how do i open and install the game... what software has to be used... help me regards abinesh