Hi! I read that you cant downgrade your psp! Im having the same problem! I get the same message "The system cannot be updated. The update system program is not applicable for this system. (80000025)"
I dont know what to do!! Do you know if your psp is 1007 or 1006? If it is, youll have to use other files... I can check for you later... Anyway... mine is 1010... ú_ù
If you figure this out, please help me!!! Hope we can downgrade our psps soon .__.