can someone please help me my psp version is 3.52 and i want 3.90 (not custom firmware)?

[Sam N]

i got version 3.52 on my psp(play station portable) but i want 3.90 i dont want custom firmware but someone please tell me any website or somthing to go to 3.90 please please please please please please please please answer i really want 3.90 if theres no way can someone tell me to go to 3.52 to any custom firm ware like for example 3.90 M33-3 i really want the custome ware that has M33-3 or m33 please please please please ANSWER