PSP Guide-Recovery Mode
You can enter the Recovery Mode on your PSP to do some configuration and hacks. To access the Recovery Mode, you must first turn off your PSP completely. Turn on the PSP while holding the R button and you will enter the Recovery Mode. You can enable the UMD option ON and OFF or do some hacks if you know what you are doing. Press the Exit to save your settings and it go back to the PSP menu screen.