iBooty-for-4.3 is automatically generated by sn0wbreeze jailbreak tool while it is doing its job building a custom IPSW firmware file. It should be located on desktop. However, if iBooty-for-4.3 not found on your Desktop, you may download iBooty-for-4.3 here.
The links will be updated whenever new version released.
You will find iBooty.exe & files folder inside iBooty-for-4.3 folder. The files folder will contains ibss.4.dfu, ibss.4.payload, notice.read, and s-irecovery.exe
Run iBooty.exe to start your tethered jailbreak device.