Cant play downloaded games on my psp my firmware or version is 3.60..i use psp slim my downloaded games are ISO and CSO

If you want to play ISO and CSO games you probably need to have Custom Firmware.

To do this you need to have a Pandora Battery and a Magic Memory Stick.

For more info on how to do this go to www.pspmod.com

If you can't do it you sure can play free games, http://www.pspdemocenter.com/list.php?c=demomenu

or

http://pspdemo.org/