New Arduino Robot not recognized by a Windows 8.1 computer.

I just got an Arduino Robot and I was testing around, uploading example code. I just had modified a sketch, but when I tried to upload, the IDE said "No Leonard found on the selected COM Port." Now when yo plug the Arduino in, Windows makes the Hardware Inserted Sound and then, about 10 seconds later, makes the hardware removed sound.

Windoze 8

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