ActiveX is just used to be able to play a video within a web browser, it is a general term
for a web browser "plugin". It is only used in Internet Explorer - other browsers (such as
Firefox or Safari) don't use ActiveX.
To enable ActiveX controls in Internet Explorer, you can do this by going to the Tools menu,
selecting Internet Options, Security tab, Internet zone, and either select the Default Level,
or selecting Custom Level and scrolling down to "Run ActiveX controls and plug-ins" and
selecting Enable.