Default [Q] ODIN & USB to PC connection problem

So I am trying to get the update for my Tmobile s3 to get it up to 4.3 from 4.1. When I go to the download mode and connect it to my computer, ODIN does not recognize it. The com doesnt show up. I know it has to do with my trying to root it but I need help on how I can solve this issue and then update my phone.

Odin Mode shows as follows:
Product Name: SGH-T999
Custom Binary download: Yes (10 counts)
Current Binary: Custom
System Status: Custom
Qualcomm Secureboot: Enable