you cant
ISO is the format in which the games of the PSP is saved as.Most of the PSP games are in ISO or CSO.So if you search for PSP ISO in a search engines, those that came up are probably PSP games for downloads.
iso and cso can either play in psp.
Actually you can play ISO / CSO in psp 3000. I've already tried this and it's perfectly working and also my firmware is 5.03, you cannot play on 5.50 . sorry pal :))
To add games to the Prometheus ISO Loader, first, ensure you have the ISO files of the games you want to load. Place the ISO files in the "ISO" folder on your PSP's memory stick. Then, launch the Prometheus ISO Loader from your PSP, and it should automatically detect the games in the folder for you to select and play. Make sure your PSP is properly configured and has the necessary custom firmware installed to use the loader.
ISO games can be played on the PSP running a 3.71 version firmware as long as the device has been modified. Games will have to be loaded onto a plugged-in SD card to be played.
Unfortuantly fellow PSP player you yet cannot play iso's on your PSP. Persevere these few months until some gets a hack. To be on the safe side, do not upgrade your firmware. I really feel for you :).
*.cso and *.iso are the formats of the psp games
Psp games (iso's and such) aren't playable in pc's... Emulators may be able to play them but you have to find one that is playable in a pc.. (If there is such a thing... )
You put games in the ISO folder.
download them on the computer then sync them on to your psp
i do know that you can play iso's of any region on a us psp slim. if that helps any http://www.myspace.com/yaboyface
on the root of the memory stick, there should be your regular PSP folders, as well as "seplugins" and also "ISO". Inside the ISO folder, you can put PSP ISO games, aswell as games with the CSO extention