Windows 2008 BRP: Local activation permission to the iis wamreg admin service required

* From the SBS console, click Administrative Tools > Component Services
(or, if you prefer: click Run > comexp.msc)

* Expand down Component Services > Computers > My Computer > DCOM Config

* Right click on IIS WAMREG Admin Service, then click Properties

* Click on the Security tab

* Click the Edit... button within the Launch and Activation Permissions section

* Click Add and add the user named: 'Network Service'
(NB: this is the step that confuses people. Most instructions simply tell you to add the appropriate user, but do not make it clear which user to add!)

* Click on the checkbox to Allow (enable) the Local Activation rights option for this user

* Click OK twice, and close Component Services

* Finally reboot the server for good measure and to ensure the change takes effect

http://msmvps.com/blogs/kwsupport/archive/2009/02/15/dcom-10016-event-error.aspx