3gs 3.0.1 to 3.1.2 upgrade
Hoping someone out there can answer me on this.....
Have an iPhone 3gs 3.0.1 serial 936 firmware 04.26.08 jailbroken using Redsn0w and unlocked.
I want to upgrade to 3.1.2 because a couple of apps require 3.1.
I've downloaded the 3.1.2 ipsw to use in the latest version of Redsn0w, but from all the instructions I've found and advice I've read, I can't fathom out what ipsw to point at at the iTunes stage and I really don't want to screw up and find myself getting updated to 3.1.3. I'm guessing the 3.1.2, but if someone out there has already successfully done this I'd appreciate a point in the right direction.
Incidentally, on Windows XP, have no access to a MAC so can't use the MAC tools.
Thanks in advance for any help.