Set security options for ActiveX controls
An ActiveX control that is unsigned is a control that does not have a valid digital signature. A digital signature helps verify the identity of the publisher of an ActiveX control and indicates that the file has not been tampered with since it was signed. By default and for your security, Microsoft Expression Web does not run unsigned ActiveX controls and does not prompt you for permission to run them. If you want to run an unsigned ActiveX control, you can set security options to enable Expression Web to prompt you for that permission.
Expression Web recognizes the ActiveX controls that run Microsoft Silverlight Movie, Silverlight XAML, Windows Media, and Flash SWF files. When you open a page that contains an ActiveX control that is unknown to Expression Web, or insert such a control into a page, Expression Web prompts you for permission to run the control. When you give Expression Web permission to run either an unknown or an unsigned ActiveX control, you are given the option to set Expression Web to Always trust and display this ActiveX control. You can set security options to clear the list of unsigned and unknown ActiveX controls that you've set Expression Web to trust.
Don't run an unknown or unsigned ActiveX control unless you absolutely trust the publisher that created the control. For more information, see Security and ActiveX controls.
On the Tools menu, click Page Editor Options.
In the Page Editor Options dialog box, click the General tab.
Under Security Options, do either of the following:
To have Expression Web request your permission to run unsigned ActiveX controls, select Prompt for unsigned ActiveX controls. If this option is clear, unsigned ActiveX controls appear as an unavailable box in Design view, only HTML properties are available for editing, and Expression Web won't run the controls and won't request your permission to run them.
To clear the list of unknown and unsigned ActiveX controls that you have set Expression Web to always trust, click Clear ActiveX Security Settings.