Which expansion board are you using? Could you post a screenshot of what you are getting in the Device Manager (Expanded in Ports and Other devices)?
Did you have problems while using the installer?
How are you powering the board?
We could try to install the standalone drivers and check if it makes a difference.
Board: Arduino kit
Here is the screenshot of the Device Manager
Installer: did not work (see below)
Power: using a 12 v supply.
The automatic install did not work for a fresh new computer running Windows 8.1 (after installing Java) , it stopped with a "Failed" message and started reverting the Arduino, IoT and Eclipse components. I have successfully gotten the kit to work on Windows 7 (also after a failed installation), so following similar manual steps I was able to get the serial ports to work (see screenshot). However, the Arduino cannot connect to the ports no matter how many times I connect/disconnect the USB cables or install/uninstall arduino software (which I have tried both manually and with the installer). Any further advice will be greatly appreciated.