[GUIDE] Return Your GSM Nexus to Stock / Flash to "takju" (now Android 4.2)

Re: [GUIDE] Return Your GSM Nexus to Stock / Flash to "takju"

Maybe a silly question, but this process DOES unroot the device, correct?
 
Re: [GUIDE] Return Your GSM Nexus to Stock / Flash to "takju"

I keep getting this error when I apply the code "fastboot flash radio radio-maguro-i9250xxla02.img"

error : cannot load radio maguro i9250xxla02.img : unknown error
 
When I enter, "fastboot flash bootloader bootloader-maguro-primelc03.img" I get "waiting for device" message back. Seems that it can't find the Nexus phone connected via the USB.
I can use Windows Explorer and view everything on the phone but try "fastboot" doesn't work.
I also tried "fastboot devices" command and it returns nothing.
I also tried the "ADB" command with same results.
I have ClockWorkMod installed and am running Jelly Bean 4.2.2
Thanks for you help.