I’m constantly seeing this in environments where the simple fix is applied (darn you IIS WAMREG and your damned Local Activation whining).
On a Windows 2008 R2 box and finding that registry key is greyed out/unavailable? Be sure to check this out first… http://www.wictorwilen.se/Post/Fix-the-SharePoint-DCOM-10016-error-on-Windows-Server-2008-R2.aspx
1. Go into regedit and expand out HKEY_CLASSES_ROOT
2. Go to CLSID
3. Find the ID by choosing Edit, Find and then searching for the string, in this case – 61738644-F196-11D0-9953-00C04FD919C1
4. Notice the service name (sometimes it won’t match what we look at next, in particular the SharePoint search one (very common), so use this as a guide
5. Launch Component Services (Start, All Programs, Administrative Tools, Component Services). Expand out to DCOM Config
6. Choose the DCOM object in question and choose properties. In this case, it is IIS WAMREG Admin Service
7. Go to the Security tab and provide the security credentials the object is requesting (look at original event ID, it wants Local Activation for the Network Service, so I’m giving it.