Expat Shield is offered as a free download at the official website. The program is compatible with 32-bit and 64-bit editions of Windows XP, Windows Vista and Windows 7. Actually, the program is not downloaded directly from the website. A download manager is downloaded first, that then downloads the application to the local computer system. The application includes a custom toolbar that does not need to be installed, so make sure you disable it if you do not want it to be installed.