HELP!?!?!?

I Have Downloaded some games from is site for my PSP Slim installed them correctly but they still dont work. They come up with the pictures and stuff for the games but when i try to enter them it just says 'The game could not be started (80020148)'.
HELP!!!!!!!!

[crait]

Do you have custom firmware on your PSP?

Sounds to me like someone may be trying to play 150 firmware games on a slim.

Which games are they?

Are you on 3.xx or higher firmware? if not upgrade. If so try to find and load the version of the game designed for a slim or for 3.xx firmware.

Most of the newer games seem to support this, also some applications such as IRShell.

Looks Like i need custom firmware but i dont know were to start all the firmware on this site seems to b an update of another. Maybe u could give me some pointers?

And atm i only got 7 games Tranformers, Legend of Zelda: Portable adventures Alhpa 4, Unoffical cave story:RTW for the slim, CSP DUST DEMO, Duke Nukem, Super MArio Toy, Guitar Star

Also u need to downgrade ur PSP ver before u can use firmware rite? I run 3.80 i can find somethingthat will downgrade that