I recently bought a Nexus 4 and I encountered a real issue with my computer (Windows 8 Pro 64 Bit) not being able to connect in USB mode. It does however work with Camera PTP mode, which I find very strange.
I have tried/tested with:
- Different usb cables
- My computer with the same OS of Windows 8 64 bit isn't connecting compared to another computer with the same OS.
- Removing its current drivers on my computer and reinstalling drivers from Nexus 4 ToolKit
- Restarting the computer
- With/without USB debugging mode
Note that the device is visible on the computer although it's not recognized: