[Tutorial] Downgrade 1.1.3 -> 1.1.1 for Win > How it works
Found this tutorial at iphone-forums.de (german)
I'll try to translate it:
1. Connect iPhone with PC
2. Download iPhuc http://**********.com/files/84214672/iPhuc.zip
3. Unpack & start iPhuc.exe
4. Type in "enterrecovery" and wait until iPhone enters Recoverymode (Notice be sure you are on iTunes 7.5 and its running while doing this tut!)
5. iPhuc window should say: <iPHUC Restore> #:
(If not, restart iphuc.exe)
6. Type in "filecopytophone WTF.s5l8900xall.RELEASE.dfu"
7. Type "cmd go"
8. Wait until iPhone Screen turns white and iTunes recognizes a device connected to it
9. Hold down shift + restore -> choose FW 1.1.2 -> let it finish -> do the same and choose 1.1.1 fw
10. Use iBrickr to kick the phone out of the DFU and go on as usual
All fame goes to puma_hh & kIREmK @ iphone-forums.de
Notice: This Tutorial won't downgrade the BB!!!