Asus Nexus 7 on my Windows 7 64 bits computer for development purposes :
I tried to install the driver for the nexus 7 manually like explained in the official tutorial of Asus
Unfortunately, I had an error, Windows couldn't recognize the driver.
I tried to change the USB connection mode to PTP or MTP by going in the storage menu and clicking on the top right menu . In both cases, windows recognize the devices but it still didn't work in debugging mode.
The only way it worked for me is by installing : adb universal installer . I scanned it before clicking on the executable, it seems to be fine.