Things to know:
I've installed Kies 3 on the computer but it doesn't recognize the tablet being plugged in either.
I've installed the Samsung USB driver.
I've successfully connected the Tab Pro when in download mode since I was able to root it.
USB debugging is turned on (also tried it with debugging turned off).
Android 4.4.2, build number KOT49H.T900UEUAND4 (rooted)
What am I missing?