What Jon says is correct - we don't currently support Windows as a platform for Cluster.
However, it's possible to have mysql client applications on Windows talking to a Cluster that's Linux boxes. So if you have a client application that must run on Windows, this would work for you (assuming there isn't too much political heck to have Linux boxes around). (you could replace Linux with any of our other supported platforms too).
We are, however, working on a Windows port and no doubt it will make it into a future release. If you really are a must-have-it-on-Windows situation - please let me know and we can keep you up to date. (I've seen evidence of processes running on Windows too - so it's not all talk - there's action). However, we would naturally not encourage anybody to deploy a solution until we're prepared to support it (a Cluster is meant to be HA after all).
The more people wanting a Windows port to work well (and going to buy support on it) the higher up the priority list it can move.
Stewart Smith, Software Engineer - MySQL Cluster
MySQL AB, www.mysql.com
Jumpstart your cluster:
http://www.mysql.com/consulting/packaged/cluster.html