How to play cso file on psp?

Cant play .cso file games on my psp?

• I have a psp slim with custom firmware 3.71 m33-2. It has a 4GB sony memorystick. Last nite I formated the memory stick as I quickly wanted to delete everything. This isnt the first time I have formated it, but the previous times I backup everything except the ISO folder to my comp. But this time I didnt (yes I knwo thats stupid). Anyway after formating the memory stick, I created the ISO folder and put a few cso files in it. But when I go to games and momory stick it says there are no games. I have been playing the same games with the same cso files for months now, so there cant be anything wrong with them. So anyone have any idea whats happening?....Maybe I am missing some files that shud be in the memory stick? (curently there is ONLY the ISO folder in the memory stick)...if that might be the case, what are those files, and does anyone know where I can download the files? Thanx

• Answer:

  Try formatting the mem stick from the psp itself.(Go to System, system, format memory stick) There should be default files and folders that is normal for psp mem sticks after that. If this is not the problem, try going to the M33 recovery menu (press and hold the power button for 6 seconds to completely shut down and press and hold the R button while switching it back on.) Go to configuration and check if UMD mode is currently at Sony NP9660 -NO UMD- and disable free UMD region and fake region. That should work.