Midi keyboard doesn't get recognised by version 1.3 in windows 7 64 bit.

I recently bought a midi keyboard ( a Behringer U-control umx490, if that matters), wich has a usb 1.1 output. The keyboard gets recognised and works fine with musescore 1.3 in my dad's pc (windows 7 professional, service pak 1 32-bit) and my brother's netbook ( windows xp, version 2002 service pack 3). However, it doesn't work at all in my laptop ( windows 7 home premium, 64 bit), even if I have installed the apropriate drivers for my O.S.. The keyboard isn't problematic, since it works in this particular laptop with virtual programmes ( kore 2 player, kontact 5, reaktor 5) and daw's (tracktion 4). I tried to connect in to musescore with batteries in, in case the problem was insufficient power supply from the usb slot, but no result whatsoever. In the I/O menu, it's not there, and I can't get it to work. It also doesn't get recognised by the portable version of musescore. Behringer can't help me. Where did I go wrong?