Devils_Advokat
Newbie
Do you know if usb debugging has been enabled on your phone? If so, I wonder if fastboot commands will work out not. I'm on my phone so is not easy to provide links right now. But simple Google search should show you how to setup a computer and phone for fastboot commands.
However if you do not know if you do or not, then mostly likely you do not. If you do not than fastboot well not work.
I dont remember If USB debugging was enabled or not. I downloaded ADB on my computer and on cmd, if I type ADB devices, the phone does not show up.