I have heard that for upgrading your psp from 3.40 to 6.20 I have to go step by step instead of jumping directly to 6.20. I want to know if this is true where can I get the previous official firmware or can I download it directly from the psp or in what folder do I have to put it in? How do I put it in the psp through usb cable? Sorry for asking so many questions but I really need help and just one more what’s the difference between custom and official firmware. Which is better? Tell me a virus free and safe site for the software. Thank you.