Updating to 3 71 m33 firmware
It took me some time to figure out how to install this update on my PSP, because of a small misunderstanding.
When you download the Update #4 (M33-4) file from any of the PSP sites, it is not the installer.
Only PSP firmware 3.50 or below can have custom firmware flashed over it without using a Pandora's Battery and Magic Memory Stick. With 3.03 and below you can use an unpatched GTA: Liberty City UMD. ---- I wrote a guide here for downgrading without a Pandora Battery: Feel free…
Use a Pandora battery and install a higher firmware with it. Load it back up and download 3.71 M33 from dark alex and just put it in your (game folder).
As per the first source link, make sure your kernal is set to 3.30 (Recovery Menu/Configuration).
Put the recovery flasher in the GAME folder and the OFW of your choice on the root of the card.
OE stands for Open Edition, a version of custom firmware that allowed people to run Homebrew applications on the PSP. So either find another homebrew which is NOT M33 eg HX or hopefully he will be pursueaded by everyones concerns.
============================= Yeah You could upgrade to 3.90.
This file will only patch an existing M33 3.52 firmware PSP with the new version.