Sounds like you don't have the adb device drivers installed on your computer. Check System Properties>Hardware>Device Manager> and see if you have "Android Phone" drivers installed. If not I suggest downloading the trial of Pdanet and installing it. This will give you the proper drivers. Then try your root procedure. Also make sure that your SD card is NOT mounted when you go for root. That seems to be one of the biggest problems people have here. Good luck!