Why is my computer saying that it does not recognize my device (samsung galaxy luna)?

[AC Question]

When I plug my phone in via USB to my pc, my computer says that Windows does not recognize it.

 

[B. Diddy]

Welcome to Android Central! When you plug it in and swipe down your notification panel, do you see anything there about a USB connection? If so, tap it, and make sure MTP is selected.

If nothing shows up, try using a different USB cable. Also make sure you're using a native USB port on the computer, and not a hub.