OpenNI, a popular open-source SDK for the Microsoft Kinect, was purchased by Apple and shut down recently. There's lots of instructions on the web about setting up OpenNI back in the day when this was a simple visit to their website away, but with the website shut down, we have to turn to other sources. The following instructions worked to get the Xbox 360 Kinect hooked up to my Windows machine.
Step One
Uninstall any drivers you may have installed for Kinect. Instead, download and install the Kinect SDK version 1.6: There are newer versions available, but this is the only one I was able to get working. Download here.
Step Two
Download and install OpenNI2. I was able to hunt down a mirror for the latest version of OpenNI2 on the structure.io website. Download here.
Step Three
Finally, download and install NITE 2.0. I was able to find this on a mirror site; the linked version worked fine. Download here: (32 Bit) (64 Bit)
Test and confirm that your Kinect is now working by plugging it in via USB, navigating to the "OpenNI2" folder (should be in your Program Files folder), going to the Tools subdirectory, and running the NIViewer.exe program. This should work, showing you a depth-map on the left side and a more typical camera on the right.