Hi Happyslug,

What you need to do is set the visible property to false on the rendering extensions.

Find your extensions in the RSReportServer.Config file e.g.

<Extension Name="EXCEL" Type="Microsoft.ReportingServices.Rendering.ExcelRenderer.ExcelRenderer,Microsoft.ReportingServices.ExcelRendering">

and add Visible="false" like so:

<Extension Name="EXCEL" Type="Microsoft.ReportingServices.Rendering.ExcelRenderer.ExcelRenderer,Microsoft.ReportingServices.ExcelRendering" Visible="false"/>

Repeat for the ones you wish to hide.