Why can't my laptop detect my S3 phone? I want to upload pictures from my S3 to laptop.

There is no problem with my cable and laptop because my phone was able to charge when I connect my phone with the laptop. However, my laptop didn't detect any device when I connect my phone in with the cable. Hence, I am unable to upload images / add songs to my Samsung Galaxy S3.
Samsung has very bad connections on that line of phones (S3, N2) I know this because I have a Galaxy Note 2 and about 6 months ago it was doing the same thing, then eventually it stopped charging all together. I also have a friend with S3 and the exact same thing had happened, except it wouldn't charge(luckily his was still in warranty).

You need to check if it is being detected in another PC, if not, the connection is broken.If you really really need to be able to plug it into a PC, you will have to buy a replacement charger dock port.

Or you can use airdroid to wirelessly transfer files to an from your PC over a wireless network.