If you open CCNA Material in the Internet Explorer, it does always Popup the Error that it doesn't want to execute these Scripts as they might be dangerous. You can click that away and work with the Course Materials - but it just tends to go on to ones' nerves. So to disable that: Internet Explorer, Extras, Internet Options, Advanced. Look for Security and enable "Execution of Interactive Content within Files on local Computer" and "Execution of Interactive Content within CDs on local Computer".