These are not OEM cables.  I bought two of these, neither one allowed me to connect my Sprint Epic 4g (Galaxy S) to my PC.  I had drivers installed and everything, they still didn't work.  I could not transfer files or root my device, it was completely unrecognized.  After doing some research, I read that many other people had this problem as well.  The solution is to buy real Samsung brand OEM cables.  I ordered the OEM cable from amazon and it worked on the first try, just had to plug it in.  This is the cable I bought:[...]