First of all, don't use a toolkit. Go into the bootloader then select fastboot. Then on your computer, open up cmd and type "fastboot devices". If that works, just post here again and I'll try to help.
If that doesn't work, you either don't have the proper drivers, or something else is wrong. The last resort would be to flash the RUU for your model. That almost always works, but will wipe everything.
EDIT: The reason why it says adb device not found is that the phone needs to boot in order to use usb debugging. If it doesn't boot, then it will never work. So do what I said above and let me know the result.