I've scoured the internet for this answer...

I want to use pwnage tool to JB my iPhone 3GS 32gb on ios4, with the old bootrom, but I don't have a Mac, and none of my friends do either. Can I download a pre-cooked IPSW and us it on my PC? Also, my phone needs to be activated again, if I restored to a cooked IPSW could I sidestep the AT&T activation? I think so. - THANKS