In ISE software 11.1, it is now possible to upgrade from a WebPACK installation to Foundation of ISE software without a full reinstall. To do this, you will need a new FlexLM license that is valid for the Foundation version of ISE software 11.1. Additionally, you will need to install the device files for the Foundation/Edition devices if you do not have them already.
To install only the device files, you should launch either the WebInstaller or the a Single File Download that includes ISE Foundation:
-Continue through the installer until you are asked to "Select Destination Directory" and pick the same location where WebPACK is installed.
-Click next. Then, for "Select Products to Install", select "ISE Design Tools".
-Click next. Then, for "Select Installation Options", deselect everything except for "Foundation/Edition Devices".
-In the next two pages you can deselect all of the environment variables and the other installation options, as these will already have been set when you installed WebPACK.
-You will now be able to access all the devices.