To access the Recovery Menu, hold R while powering on the PSP.
The recovery menu is a feature of custom firmware. It allows you to recover, customize and Setup your PSP .
Toggle USB
This enables you to access your PSP's memory stick over the USB connection.use this if you cannot enter the xmb.
Configuration
This enables you to configure some options. All settings are disabled by default.
Skip SCE logo
This disables the Sony Computer Entertainment logo from playing when power on the psp.
Hide corrupt icons
This hides the corrupted icons generated by Kxploited homebrew (homebrew that comes in two folders). This can slightly slow down your GAME menu if you have a large amount of homebrew.
Game folder homebrew (currently 3.XX Kernel)
This lets you choose whether to load programs with the 3.XX kernel or the 1.50 kernel.
Autorun program at /PSP/GAME/BOOT/EBOOT.PBP
This will allow you to run the EBOOT located at /PSP/GAME/BOOT/EBOOT.PBP whenever your PSP starts up. This feature is used by some homebrew programs . Any eboot run in this way will run on the 1.50 kernel.
NO-UMD Mode
This will enable you to run backup games iso/cso from your memory stick without needing to have a UMD in the drive. there are 4 options:
-off: you will need a umd in the drive to play isos
-sony np9660: 100% compatibility.:Recommended
-OE legacy: the old OE no umd driver. not very compatible
-M33: DAXs attempt to equal the sony driver. Nearly 100% compatible
Fake region
with this option you can set the psp region to Japan, USA, Europe or Korea. Setting the region to Japan enables you to visit a video download service (Portable player) through the Network section of the PSP's main interface, but it is impossible for people outside of Japan to download the videos .
Free UMD Region
This enables UMD movies and music to run region-free.
HARD RESET ON HOMEBREW this option isnt usefull anymore. USE vshmenu
enables vsh menu ( a mini recovery menu which you can access in usb by pressing SELECT)
XMB Usb device This allows you to change the dieve you plug into the pc when u select usb mode. For example. if you set this to flash0, when you use "usb connection" in the xmb, it will connect flash0 as if it was a ms. Charge battery when usb cable is plugged in
For slim only, when the psp is plugged into usb it will charge even if its not in usb mode.
Run program at PSP/GAME/RECOVERY/EBOOT.PBP
This will recover your PSP if it has been semi-bricked.
Advanced
This enables you to configure some advanced options and mount your PSP's internal flash to your computer via USB. Messing with this without knowing what you're doing can result in a Semi-Brick or permanent brick.
Advanced Configuration
This enables you to configure advanced options.
Plain modules in UMD/ISO
This allows certain forms of unsigned code to be run from within an ISO. There aren't really any practical uses to this function, and it can make some UMDs and ISOs incompatible with your firmware. Developers can use this function to experiment with running homebrew from within an ISO.
Execute BOOT.BIN in UMD/ISO
This runs BOOT.BIN inside the ISO instead of EBOOT.BIN. Useless unless you're a developer experimenting with the Plain modules in UMD/ISO feature, you shouldn't use this feature; average users have no need to toggle this.
Use isofs driver also in UMD-inserted mode
Runs UMDs using the ISO driver. For non-developers, this will do nothing more than reduce compatibility.
Toggle USB (flash 0)
This enables you to access your PSP's internal flash 0 memory over the USB connection. Messing with these files can result in a brick; there is simply no reason for the average user to use this feature.
Toggle USB (flash 1,2,3)
This enables you to access your PSP's internal flash 1, 2, or 3 memory over the USB connection. Messing with these files can result in your settings becoming corrupted.
Format flash1 and reset settings. This resets your psp back to factory settings. It wont brick your psp, but you will lose all network connections. CPU Speed
These settings enable you to change how fast the CPU runs in games and in the PSP's interface and web browser. Higher numbers will result in better performance at a cost of battery life.
Speed in XMB
This determines how fast the processor will run when it isn't playing games. If you browse the internet or watch movies, you might want to increase the speed.
Speed in UMD/ISO
This determines how well games will run. The higher the value, the higher the framerate. If you experience any slowdown in a game, increasing this number should eliminate it.
Plugins
You can use this menu to enable any PRX plugins that you've copied to your seplugins folder.
Registry hacks
These settings allow you to change a few registry-related settings in the firmware.
Button Assign
the X and O functionality seemed to be switched on the japanese version.
This allows you to change circle or X as the enter button.
Activate WMA
Enable wma playback without network connection. Official 3.03 won't let you enable this without connection to Sony's servers using a wireless internet connection.(wifi)
Activate Flash Player
This allows you to activate the PSP's Flash Player. Official 3.03 won't let you enable this without connection to Sony's servers using a wireless internet connection.(wifi)
Exit
To exit the Recovery Menu and restart the PSP.
How to Recover to 1.50 from the Recovery Menu (old) and wont work on a slim
This can be used to fix your PSP if it
Semi-bricks, as long as you can access the recovery menu.
Download and Extract the
RECOVERY folder(Winrar recommended)
http://www.zshare.net/download/recovery-rar-ar7.html
Copy the
RECOVERY folder to PSP/GAME/
Start your PSP in Recovery Mode, then choose "Run program at /PSP/GAME/RECOVERY/EBOOT.PBP". Read the instructions and press x. This will Downgrade your psp to 1.50 version. Don't shutdown the PSP or remove the memory stick until the update is finished.
Once finished, shutdown the psp and restart manually to 1.50.
How to enter Recovery Mode?
Turn your PSP completely off by holding the power switch for several seconds. When you turn it back on, hold the right trigger until you enter the recovery menu. 
Linear Mode
