Instructions
Take your PSP in hand and press down on the power button located on the bottom right corner of the unit. Hold down the power button for approximately 5 seconds to ensure that the power is off.
Hold down the Select button and Start buttons (both located in the bottom right side of the unit), and the Square button and Triangle buttons (located on the button pad on the right side of the unit) simultaneously.
Press the Start button again to restart the device while continuing to hold all four of the buttons.
Release all four buttons once the flash (logo) screen appears. Your PSP will now be reset to its original factory settings and all bugs, including the blue screen of death, will be wiped from the device.