Try TocaEdit Xbox 360 Controller Emulator (it's free). Windows is ironically pretty lousy with assigning your USB input controllers by default. It typically assigns controller #1, #2, 3, etc in order by when they are plugged in, though after a reboot--the order may get switched around. Perhaps it varies by motherboard; I'm sure there's a reason for it.
TocaEdit allows you to completely change and assign the input order to whichever slots you want for which USB devices.
It's very versatile and features a lot of different options to play with. So much so that you can use it to map a HOTAS and rudder pedals to fly planes in games that can't bind to HOTAS inputs (like Battlefield 1--at this point in time at least.)