Default HDX 7 root issue

hi ,

today i try to root my HDX 7 follow the way :

Rooting tutorial - hdx 7"

when i run runme.bat , it shows:

attempt acdb exploit...
KFTHWI (JDQ39) is not supported .

and the other process is same as the root thread. when i installed supersu it shows update, but i can not . idonwload rootchecker and found my root is not completed .....who can help me.....