Brewology

i Don't Know How To uSe It Help Someone

ok wen u click it go down to umd and select either your iso or any umd then hit start.

make sure you install it with the 2.71 firmware, then on your psp
scroll down to firmware select and select "2.71" by pressing O then
go back up and press "start".

I assume you have installed it (if not) if you have installed it, then this is how we load an ISO with a UMD in the drive.
Booting game backups in 2.71 emulation with a game UMD in drive
This is supposed to work for all version 2.71 games and below, as untouched ISOs, which can also be compressed in CSO format. Also please note that many games only needs the UMD in drive only until they reached the start screen. If the game seems waiting (usually when loading stages) or sounds suddenly missing, put back the UMD in drive. Eg: Worms needs an UMD only to reach start screen and while loading the levels. Also see the Devhook 0.4x compatibility list for more info.

UMD SELECT: select your ISO
UMD MOUNT: ISO ANYUMD
UMD VERSION: no change
FIRMWARE: 2.71(MS hook)
CPU CLOCK: 222 Mhz (333 if experiencing lag but network functions will have issues, see T08 about this)
BOOT SELECT: Reboot XMB
PL-ADR: 89000000 (in: OTHER/preload address menu)

.... He it talking about using Devhook on 2.71

you need to find the TIFF Expolit file, then you need the 2.71 eloader to run the HEN Revision C so that you can now launch homebrew and Devhook.