Restore 3GS to 3.12

Hello
I jailbreak my iPhone 3GS (MC model) with blackra1n few months ago and everything was perfect(I had to run blackra1n after reboot but that's ok..), but yesterday I have some trobules with WiFi so I "Reset network settings" (in menu General).
After that my iPhone reboot and i tried to run blackra1n again but it stucks at the picture of this face.
I tried too restore from file to 3.12, but as you know it can't be done bacause itunes don't sign 3.12 anymore.


I tried to restore with custom firmware:
I'm using Win XP and download custom firmware .ipsw files from internet.
Ok, it looks like it's ok but it stucks a "preparing ..."
I also try DFU mode but it the same...
After a longer time there are errors like 1600,1601,1602
Maybe if I use other ipsw custom firmware it would work? But I dont have Mac so i even can't create custom .ipsw :(

Could anyone help me with restoring to 3.12?
I DIDN'T update to 3.13 beacuse i read it's even worse option.
But now i can't use my phone at all :(

whenyou first unlocked you iphone did you install cydia. if yes did you participate on make my life easy on cydia?

I don't remember but probably I didn't, because I can't download this file ECID SHSH, with Umbrella from Saurik (Cydia) server. Yes I know that was mistake, but I didn't think about it that time.

Is there any solution now ?

There are no solutions without a valid SHSH for 3.1.2 or lower for your phone.