well an easier way would be to put in a new game n update it freom the game or you could put cutsom firmware on it abd then you can runbackups of games =]
custom firmware 5.00 m33-4 cannot be installed with versions lower than 3.70, you should download version 3.70 first and them install it following the instructions which will be displayed on the screen. after that you can then download version 5.00 m33-4 and install it on your psp.
If you ask me i prefer custom firmware 3.71 m33 its really stable and all downloaded games work fine on it.
February 5th, 2010 
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well an easier way would be to put in a new game n update it freom the game or you could put cutsom firmware on it abd then you can runbackups of games =]
heses a tut on how to do it
http://ultimatehub.smfforfree3.com/index.php/topic,49.0.html
u need to download the sony update as well as the cfw update that the only way it works
jump from 3.40 m33 to 3.52 m33 then to 3.71 m33-4 and finally to 5.00 m33-4 the latest custom firmware.. any more questions? go here pspiso.com..
custom firmware 5.00 m33-4 cannot be installed with versions lower than 3.70, you should download version 3.70 first and them install it following the instructions which will be displayed on the screen. after that you can then download version 5.00 m33-4 and install it on your psp.
If you ask me i prefer custom firmware 3.71 m33 its really stable and all downloaded games work fine on it.
this is where you can get the custom firmwares:
http://www.pspiso.com/showthread.php?t=83780
Pandora’s battery is the easiest method to put cfw on your psp