Need help jailbreaking and unlocking 4.2.1 3G
So... I had my already unlocked and jailbroken iPhone 3G with iOs 3.2 I bought from ebay for a while now, and I just decided to update it to 4.2.1 and re-jailbreak it after hearing about how "easy" jailbreaking is, but now, it's stuck on the emergency call only screen since it's not unlocked anymore and I didn't actually manage to jailbreak it in any way...
I updated to 4.2.1 using iTunes, and after I found out I can't do anything with it (since it's stuck on the emergency call only screen thing) I tried to jailbreak it with several programs (blackra1n, greenpois0n, redsn0w) but none worked.
The most further I got was using redsn0w - which actually got to the end, but it didn't reboot itself (like it should have? I can't recall exactly what it said, but I'm 100% positive it made it to the end) and when I tried to reboot it myself I found myself again on the emergency call only screen :\
What do I do?
And just for the record - I have W7 not OSX.
Thanks in advance.
EDIT: I just remembered, redsn0w said something about being ready for custom ipsw, but I had no idea where I'm supposed to get it from... sorry for my nubbishness.
EDIT 2: Nevermind, I figure out what I was doing wrong, I didn't tick the right settings on the redsn0w. Now it's working fine, so feel free to lock/delete this topic.