This policy setting controls whether ActiveX controls are disabled. If you enable this policy setting, Office 2013 applications ...

This policy setting controls whether ActiveX controls are disabled. If you enable this policy setting, Office 2013 applications do not initialize ActiveX controls from non-trusted locations, and do not notify the user that the ActiveX controls are disabled. If you disable or do not configure this policy setting, users can set the trust level for ActiveX controls in the Trust Center in the 2013 versions of Microsoft Access, PowerPoint, Word, and Excel. The default configuration does not load untrusted ActiveX controls, but uses the Message Bar to prompt users about the control, and they can then choose whether to run the control.