Official Custom Firmware Guide
The Official Guide for CFW.
Hello and welcome all! Note: The most compatible Memory Stick is the Sandisk Magicgate 2GB Pro Duo, but this works on many other Memory Sticks.
1) You must create a Magic Memory Stick to use Custom Firmware. The Magic Memory Stick, or MMS, is the easiest thing to create. To open the file you with the MMS maker you MUST DOWNLOAD THE FOLLOWING: http://www.winzip.com/downwz.htm This is entirely free for 45 days.
2) Then, all you must do is go to http://www.filefactory.com/file/af9c9bb/n/25437_RainsUltraLiteMMS500v12_zip and download the file. I believe you must type in something to show you are human, and then wait 30 seconds. This file does not have any viruses, I scanned the file with multiple different up-to-date anti-virus software programs.
3) Next, extract the RainsUltraLiteMMS file and drag it onto your desktop. You may exit out of the winzip program, as the README document is useless.
4) After saving the RainsUltraLiteMMS to your desktop, go to http://downloads.pspspot.net/firmware/762-5-00-official-psp-firmware.html and download the Sony 5.00 official firmware. Once you open this with Winzip, extract the file UPDATE.PBP and drag it to your desktop. You MUST RENAME THIS FILE THE FOLLOWING: “500″ (Take Away the Parentheses)
5) Double Click on RainsUltraLiteMMS to open it up. This is where you do one of the following. If your computer is capable, you may literally take the Memory Stick out of the psp and place it in the MMC/SD drive. Otherwise, you must leave the Memory Stick in the psp and hook the psp up to the computer via USB cable.
6) RainsUltraLiteMMS should automatically detect your psp and select the drive letter, but if it does not go to the drop down arrow near Drive Letter and select which drive your psp uses.
7) It is HIGHLY recommended to format the memory stick, and backup the memory stick. This way you have a clean memory stick, and all your precious files are still safe. You can activate these setting by checking the boxes to the right of the program.