Trying to install ADB USB Drivers, but Nexus is never appearing in Device Manager I'm trying to install the google-adb-drivers.zip file (obtained here) on a Windows 7 64-bit system. The phone is the Nexus S 9020T. USB connectivity works correctly for file transfer mode. When I enable debugging, I expect to see "Nexus" appear under "Other Devices" in Device Manager, but it doesn't. After checking USB Debugging under "Developer Options" in the phone, the computer makes the USB disconnected sound. 

I was able to load the drivers on a different Windows 7 32-bit system, but that's not the system I want to use. 

Why is the debugging port not being recognized on the 64 bit system? 

I saw the other post with a link to download the SDK, but I also would like to avoid installing the entire SDK unless absolutely necessary.
You should get the proper USB driver via the SDK Manager (which is the the tool you will run when installing the SDK).

The first step in installing the SDK, is starting the 'SDK Manager", and downloading an Android API package (ie. the code to develop for a specific API)

In the list of options, is an 'Extras' section - that contains the official USB driver for Android developer devices (of which the Nexus S is one).  Download that driver for best results.

You won't need to install the whole SDK using this method, but will need to start down that path, in order to get the proper driver.

Good Luck.