Airport utility is not working on Windows. I can configure Airport Expresses with the Macbook but multiple computers with Windows and the latest Airport Utility time out after trying to connect to the router for setup.

I have been trying to setup Airpot Expresses (both old and new models) for a while now with the Airpot Utility 5.6.1 for Windows without any luck. I have tried this on multiple windows machines, factory reseted the devices if I needed to, but I have not had any success since this software arrived. I see the routers on the Airport Utility UI, I click on it then try to connect to set it up. At this point, it gets stuck with a long progress bar trying to connect to the device without any success. I also have a Macbook Pro, and this device & software has had no trouble setting up the routers. The problem is, we are shipping these small routers out to customers who use Windows machines and it is vital that the user can modify the settings using Airpot Utility. I am at a loss for what to do and if we can't find any solutions, we are going to move on to a different company for the routers we ship out.