I have an Arduino Leonardo, bought from RS electronics, and when I plug it in, it shows up as 'ATm32U4DFU' under 'Other devices' in Device Manager. I've tried Update Drivers with the 'C:\arduino\arduino-1.5.5\drivers' IDE folder, and with the 1.0.3 folder, and with the 1.0.1 folder, but nothing... I unzipped 'Old_Arduino_Drivers' and it doesn't find it in there either.
I ran 'dpinst-amd64.exe', those drivers installed successfully, but it doesn't show anything different under Device Manager.
In the IDE, the 'Ports' is greyed out, and it can't find the Leonardo in any of my USB ports.
Any idea what to do??