Can I use PSP Installer Deluxe v2.2 to go from 3.40-OE to M33 firmware?

[muppettom]

Hi, I'm contemplating upgrading from 3.40-OE but I have lost my recovery menu so I am walking a tightrope. I was wondering whether this might be able to perform th process simply (i.e. not having to mess around compiling) and hopefully safely?

[jxx2005]

you can go right to 3.52 m33 from 3.40 oe
i did with no trouble
you need to download the 3.52 official firmware upgrade from sony
and find somewhere to download the official 1.50 firmware installer
but once you get those (and teh obvious 3.52m33 files) then it should be simple

[muppettom]

Okies, could you reccomend a good guide or some decent sources for the firmware? I'm not too confident following engrish instructions from Russian, despite the fantastci work the devs have done.