Troubleshooting: Why are browser features all recorded as null for Internet Explorer?

With the exception of cookies and Java, our JavaScript tracker cannot detect what browser features (PDF, Flash, etc.) a given instance of Internet Explorer has. This is because IE, unlike the other major browsers, does not populate the window.navigator.mimeTypes[] and navigator.plugins[] properties.

There are other ways of detecting some browser features (via ActiveX), but these are not advised as they can trigger User Account Control warnings on Windows.