Windows terminal not finding adb device

I'm attempting to flash android M on my nexus 6. I've installed the proper drivers from google, after checking in device manager it says the proper drivers are installed. When I enter "adb devices" into the terminal nothing shows up in the list. I've searched through forums and tried the universal adb installer which isn't compatible with Windows8x64, so I used the 15 second installer which worked but didn't change the result. Am I doing anything wrong?

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