Nexus 5 USB driver

Question

I want to develop and debug Nexus 5 with ADT (based on Eclipse) in Windows 7 x64.

As I connect Nexus 5, it appears in Windows in Explorer, so I can

Answer 1

Is it your first android connected to your computer? Sometimes windows drivers need to be erased. Refer http://forum.xda-developers.com/showthread.php?t=2512549