I am not able to use the "Add or Remove Programs" utility in Windows to uninstall the ISE Design Suite tools. How can I uninstall the tools?
From ISE Design Suite 12.1 onwards there are no longer any Xilinx entries in the Windows Registry.
All of the information that was in the Windows Registry is now included in the installation.
As a side effect of the ISE Design Suite tools no longer using the Windows Registry, it is no longer possible to use the Windows "Add or Remove Programs" utility to uninstall the ISE Design Suite tools.
Instead, you can uninstall the tools by going to the Windows Start menu and running the Uninstall process located in the Accessories folder within the Xilinx ISE Design Suite Start Menu program folder.
Alternatively, you can run "xsetup -uninstall" using the xsetup executable found in the common folder. This is also the method to uninstall on Linux.