this is Raphael from the Datacolor Spyder tech support.
In the older version of this forum was a thread regarding this subject I couldn't answer, so please allow me to open this thread here and clarify a few things:
Our Spyder3 calibrators (all 3 versions Elite, Pro and Express) are compatible with the Windows 8 operating system.
Just make sure to install the very latest version of the Spyder3 calibration software from our website.
In case you got technical questions/issues please contact our support team directly.
You will reach them by submitting a support ticket in our ticket system under: support.datacolor.com