iBooty v2.2 is automatically generated by sn0wbreeze v2.8 beta 1 while sn0wbreeze building a custom IPSW firmware file for iOS 5 beta 1. iBooty.exe available inside iBooty-for-5.0b1 folder on Desktop. Use Use iBooty v2.2 to boot your tethered jailbroken device if you jailbreak by using sn0wbreeze v2.8b1.
However, if iBooty-for-5.0b1 folder was not found on your Desktop, you may download iBooty v2.2 here.
You will find iBooty.exe & files folder inside iBooty-for-5.0b1 folder. The files folder will contains s-irecovery.exe, notice.read, llb.4.dfu, and llb.ipad.dfu.
Run iBooty.exe to start your tethered jailbreak device.
If you really need a guide how-to use iBooty to tethered boot iOS 5, read How-to Use iBooty for iOS 5 (different example, but the steps are remain the same)
Note: iBooty for iOS 5 only available on Windows, not available for Mac. You may use redsn0w 0.9.8 for mac instead.