If what Zero said doesn't do the trick you could try the following.
Check in the installation folder, there may be an "install" and a "setup" or "launch" file. If you can just run the install file it may bypass the shield altogether. Of course you should not do this without anti-virus software running and it may not show up in your program installation settings. If you ever want to remove it there should be an "uninstall" file that copies to the game folder or you jusr would need to delete it outright. Good luck!