How do i play iso files from a memory card* on my psp go?

so my psp go is already hacked and all. im on cfw 6.20 pro b6. i have iso files on my internal memory in the iso folder and they work fine. but i just recently bought a memory stick and put it in and created an iso folder on the stick on the directory computer/removable disk (h:)/ ISO and i go back to my psp and go down to the memory stick under game and it just says i can download stuff from the psn store. so basically nothing shows up on my memory stick on the psp D: could someone possibly help me out?