Nexus 5 not detected by ADB
One thing I noticed not mentioned in what you have tried that will make your device invisible. Have you enabled USB debugging  on your Nexus 5. USB debugging helps operating systems communicate with each other and without it things get lost in translation. To enable USB debugging


Go into Android settings menu and scroll down to the about phone menu next go towards the bottom and hit the build number 7 times. 
settings/about phone/build number
This will reveal a new menu within the main Android settings called developers options and scrolled to USB debugging and enable it.


That should get you up and running but if not then scrap the the driver you modified. Go to SDK redownload Google drivers and install them. That issue  was reported in 2013 and the drivers in SDK have been updated since.