You've just unpacked your UMIK-1, plugged it into your PC/Mac yet you're not able to see it as a device. What's going on? Isn't it supposed to be plug&play and driverless? It is indeed!
For one, while failure can happen, the likelihood that a UMIK-1 is faulty is quite low knowing a mic is being QC 4 times on the chain. The last step being the calibration file process right before it is packed.
The likelihood that the USB isn't pushed all the way in is going to be very high. On a first-time use, you really need to push that mini USB cable all the way in knowing it's a tight fit on the USB connector. It's an intentional "design" feature of the mic to ensure that the connection isn't lost as you move the cable around. Trust us, we've shipped enough mics to know it's worth it. :-)
The second troubleshooting test is to make sure you're not using a very long USB cable. USB 2.0 is rated 5m max so make sure you're not using a crazy long cable extender. Else it's most likely not providing power to the UMIK-1 body (even if that little LED is on).
Any other issues? Keep us updated and we can take it from there.