If you tap on the USB network setting text it will open that dialog box.
First 2 pics are before I update the android.Last pic is after update.
When I to connect my phone to PC i use internet from my Pc to phone, fot that i need to activate the "Internet pass-through.
Does anything pop up after you tap the text?
Download the newest version of HTC Sync.
It looks like your best bet is to unlock the bootloader and flash a Sense 6/Android 4.4.2 ROM. Or wait for your carrier to release an official OTA to 4.4.2.