Right Click on the Nexus 5 and select Update Driver Software. Xperia Z Ultra SGP3xx including WiFi Only SGP412, SOL24. Sony Z Ultra Google Play Edition. Now from the next screen click on the Browse my computer for driver softwareStep 6. From the next windows click on the Browse button and select the Google USB Driver folder that you downloaded on the Step 1.
And keep the Include subfolders box checked. See the Screenshot below:-Step 6.