I had to go to samsung.com and get a driver for that phone. After that it worked. Since this was a PC issue and not a phone issue, ATT and Samsung don't give free support.
I have been having issues connecting my Samsung Galaxy S3 to my computer since the day I got it from AT&T. The computer registers that something is plugged in but will not bring it up in "Computer" as a hard drive and Samsung Kies tries to connect to it and brings it up by its Product Number "SGH-I747" but again will not connect. Has anyone else encountered this problem, and if so did you resolve it and how.