I am unable to get my S3 to connect to the computer. I have the drivers for the phone, but it just doesn't seem to work. Windows 8.1 sometimes sees the phone, but it doesn't stay connected for long. Windows XP only sees an unknown USB device connected.
I recently took my phone to the Samsung desk at Best Buy to ask about the different versions of 4.3 going around and they had trouble getting the phone connected to their computer. They thought maybe I have a loose port on the phone.