first download and install these drivers: revolutionary drivers
then,download this small file:
-unzip it,and place the unzipped folder onto the root of your C drive(not inside a folder)
-open a cmd window(with win 7,click start bubble,type "command" or "cmd" in hte search box)
-now change to your mini-adb directory(assuming you didnt chagne the name). type in the black cmd window that opened on your PC:
-pull the battery in your phone for a few seconds. hold volume down,then power. hold them both until you see the white/colored writing hboot screen
-select "fastboot" from the hboot menu with the vol rocker/power button
-in your cmd window type:
it should output your phones serial number. if so youre good to go. if not,youre apparently having a driver issue. i usually recomend these drivers from Revolutionary
: modified htc drivers
download and install the drivers(you should just have to run that file). afterwards,unplug your phone,plug it back in. make sure its in fastboot. as soon as you get a result from "fastboot devices" your ready to procede to the next step.
-in your cmd window,type(or copy/paste,is much easier):
fastboot getvar all
-copy the info that outputs here. right click in your cmd window,click mark,highlight it all in white. hit enter. paste the info here. it will help us know which ruu for you to run.