How do I upgrade the firmware on my PSP Slim from 3.71 m33 to 3.90 M33?

I have my psp with 3.80, and without downgrading can I upgrade directly to 3.90 M33? If not, please explain how I can achieve the upgrade to 3.90 M33 from 3.80 normal.

ok i had psp 1.5 for a long time and was doing great, then today i upgraded my 1.5 to a custom firmware 3.52 m33. everything was great. the games/isos workd perfect. until i wanted to try the psx on psp. to do that i had to go recovery mode and go pluggings...

I have currently 3.93 official sony software on my psp and want m33 firmware! i dont want to do a pandoras battery of course but will i be able to upgrade to 4.0m33 when it comes out (im not sure if it will be 4.0 or 4.01 or maybe something else)

Hi, Im new to PSP and I have a Custom Firmware (CFW). I was just wondering whether I need to downgrade my CFW to 1.5 using a certain application so I can upgrade to another higher CFW? For example, I have a CFW of 3.71 M33 and I want to obtain a CFW...

ok, i have the 4.01 firmware on my psp and i want to get a custom m33 firmware so i can put games on my psp. all the upgrades i found say "game not found" when i run the cfw (custom firmware). so how do i upgrade to 4.01 m33 cfw and where can...

OK,I'm new to the PSP Console.I got a PSP Phat and it is running CFW 3.52 M33.How do I upgrade it to 4.01 M33? I googled it and all the tutorial does not work.Sometimes,I download the wrong file and sometimes,I downloaded viruses which is titled as the...

Hey, my friend recently gave me a psp, but it is custom firmware 3.71 m33-2, and I can't upgrade it to play the game i want to play, which needs at least a 6.31 version. So how do i get the custom firmware version back to the official firmware version...

i want to play psp again. I haven't played in a few years. The version it is running right now is 5.00 m33-3. I see that the newest firmware is already 6.xx. Do I need to upgrade to that in order to play new games and also playing them online? Do i even...