Have you looked in the device manager in Windows to see how it has your device labeled when you are comnected and in fastboot mode? This can tell you for sure if it is a driver issue as it will show a yellow question mark if the drivers are not installed. Download the .exe to install the
latest lg drivers from here. Like I said before you need to have your device connected when you install the drivers and you may have to connect your device in fastboot mode and re install the driver also.
Now if you want to use linux you can make a bootable flash drive to boot Ubuntu and use it. You just need a flash drive that is atleast 4 gigs. Just google how to make a bootable flash drive for Ubuntu in Windows and you will find toms of very easy to follow guides online. Once you have a bootable flashdrive(or if you choose to just install Ubuntu) you can use install adb and fastboot by entering the following commands in terminal.
sudo add-apt-repository ppa
hablet-team/tools && sudo apt-get update
Then this one.
sudo apt-get install android-tools-adb android-tools-fastboot