[M2Iceman]

The Serial number you need will be "shown/displayed" by the Revolutionary SCRIPT in your dos window. Download the Revolutionary tool *LEAVE THE BROWSER WINDOW OPEN, unzip, follow instructions (above) for debug and plugging in the phone and when you run the revolutionary exe it will give you a serial >>>>> Go back to the revolutionary browser window and put in your OS Device, Hboot and then the "serial" number shown in the dos prompt window the script created.

I got this from XDA because I was not understanding one of the steps but I did this to my step sons Evo and can verify I just rooted his GB Evo.