Can't see mp3 files in Windows 7!

OK, I plugged the Sansa c250 into a cheesy work computer running Windows XP and Voila! I can see all of my mp3s on the device just fine in Explorer. But when I plug the device into the USB2 port of my Windows 7 Home Premium 64-bit cutting edge laptop, I STILL CAN’T SEE ANY OF THE MP3s! What the heck is going on here and how do I fix it? I need to be able to edit these files on my laptop…