Can someone help me connect my S4 to my PC via USB?

[Jane Stolworthy]

Problem with PC connection

Can anyone help me? I am having a problem when I connect my S4 to my PC using a USB cable. The phone begins charging but I am not getting the pop up box on my PC and when I go into My Computer, the phone is now showing. This of course means I cannot copy photos from my phone etc. I have tried Kies but that is not seeing the phone connection either.