Hi, hope this helps.
I just bought a galaxy s3, and had the same issues. several hours on support with both the geek squad, and Samsung. that proved my opinion that an outsourced overseas help desk, who barely speak English, and cannot read the support script are not that helpful.
I downloaded the drivers, and installed KIES, but could not connect to my windows 8 HP laptop.
I was able to connect when I moved the USB cable to a USB 3 port. I verified this was the resolution on multiple other pc's, and by using the ports on my docking station. for windows 8, you do have to download the drivers from Samsung. for windows 7, the OS is able to recognize the phone without a manual download (windows update).
hope this helps!
Don't use the USB cable that came with the phone. I got an old USB cable (the one that came with my HTC EVO that I bought 2 years ago), connected the phone to my laptop and that worked.
For some reason, the cable that came with my GS3 only works for charging, not SD access via a computer.
What worked for me was just disconnecting the USB then going to 'Developer options', check USB debugging.. restart the phone and plug the USB back in. Both my folders showed up after that. I can now drag and drop things into my phone with no problems. I hope that helps!
Here's what worked for me after literally trying everything under the sun (compiled steps from various sources):
Steps to Safely Cleanup and Remove old USB Mass Storage Drivers on your PC
Shut down your computer. Unplug your USB storage devices: USB Disks, flash, cams, CD/DVD, etc.
==> Other USB devices like keyboards, mice and LAN adapters can stay plugged in
Boot computer back up. Click for how to determine whether you are running 32 or 64 bit Windows
Download drivecleanup.zip, unzip and save to your desktop. Move the 32 or 64 bit version of DriveCleanup.exe toC:\Windows\System32
Open a command prompt window as follows:
==> For XP only: You must have Admin privileges. Click Start->Run, enter cmd
==> For Vista and Windows 7: You must open an elevated command prompt window!
After the command prompt enter: drivecleanup.exe
==> Your command prompt window should be similar to my example below.
==> If, instead, you get an error message like Command not recognized it means you didn't move Drivecleanup.exe to the right directory
Download the latest USB drivers here:Support - AT&T Cell Phones SGH-I747 | Samsung Cell Phones Click the tab at the bottom that says "Manuals & Downloads" then Software then the link for the Device(Install),USB Driver (Software) (ver.v18.104.22.168)
Unplugged or disable your internet connection ***CRITICAL***
On your S3 go to Settings>About device>Check for updates and install the update (eventhough we next do a hard reset the new firmware is worth it if only for the brightness feature added to the notification drop down).
Do a hard reset on your Galaxy S3 instructions for that here: Samsung Galaxy S3 hard reset - PDA Smartphone PNA hard reset soft reset
Turn on S3 (without USB plugged in) and don't login to your Android account ***CRITICAL***
Plug in USB and it should install all the drivers at long last ***SIGH***
Login to your Android account with the USB plugged in and you should be good to go!
I hope this works for you because I went through probably 8hrs of B S trying to figure this out. Believe when I say I tried EVERYTHING and this is only fixed it! Oh one other nice thing is this fixes the annoying COPY/PASTE issue as well. I know it's pain in the neck but it's worth it.
I'm on a Window 7 Ultimate Service Pack 1 32-bit machine.