Things I've tried:
-Rebooting the PC(Many times)
-Rebooting the phone(Many times)
-Powering off the phone, taking out the battery and leaving it for 5 mins then powering on again
-Reinstalling Samsung Kies and Samsung USB drivers(infinite times)
-Factory resetting the phone and skipping all account prompts at startup then connecting the phone(seems to work for some people)
-Connecting with USB debugging off
-Connecting with USB debugging on
-Changing the USB Port.
Please help, I'm just about sick of this phone and it's countless issues, can't believe how hard it is to customize.