HELP with upgrade and Unlock! 3GS 5.13.04

[J0ej0e]

Hey i desperatly want to upgrade to 4.1!
Im sitting on iphone 3gs 4.0 right now Unlocked and JB, Old Bootrom, 5.13.04

I have a Windows PC and need to know what tools i can use to preserve my baseband for future unlock.? this stuff is so confusing to me and would appreciate the help!

[Simon]

The easiest course of action for you would be to download tiny umbrella and save your 4.1 SHSH now. Then when the new unlock comes out (which may be as early as this weekend) update to 4.1 then unlock with the new unlock. Do not do that until it is released though.

If you really want 4.1 now then you have two options:

1: If you used jailbreakme.com to jailbreak you need to install jbme2pwn from cydia then make a custom 4.1 with sn0wbreeze and shift-click restore to that in itunes. This will preserve your baseband so you can still unlock with ultrasn0w.

2: Gain access to a mac and use pwnage tool to make a custom 4.1 and restore to that.

[manishkatiyar]

This the the best comprehensive list of options you have:
Jailbreak iPhone 3GS 4.1