Wifi AWUS036NH working in 10.9 but with no Internet
Try following these instructions. Condensed version is below.

Turn off Wi-Fi.

Open Finder, press Command+Shift+G then enter the path below and click Go:

/Library/Preferences/SystemConfiguration/


Find and delete the following files (some may not exist):

com.apple.airport.preferences.plist
com.apple.network.identification.plist
NetworkInterfaces.plist
preferences.plist


Reboot.