Today I went to install the arduino IDE on my new laptop (windows 8.1). At first, the Arduino kept coming up as an unknown device, so I went through instructions from this thread to force install the drivers http://forum.arduino.cc/index.php?topic=127801.0. When I do that, it keeps popping up with the error code 10, "Device could not start", in the driver installer page. Help! there is a screenshot below showing the error code, if that helps.