I have seen this several times and been asked about it as well.  If you see DCOM errors in event viewer that state they do not have the right permissions, usually launch permissions you will get something like this:

Source: DCOM EventID: 10016

The machine-default permission settings do not grant Local Activation permission for the COM Server application with CLSID

{2D527A8C-A4B6-4E74-A63F-E867360D401C}

to the user DOMAIN\username SID (S-1-5-21-2060139532-2050374463-2073913816-37548). This security permission can be modified using the Component Services administrative tool.

You then to to Start —> Run and type dcomcnfg, navigate through Component Services down to DCOM Config, you look for the GUID and you can’t find it.  Well there is still hope.  You can match the GUID to the server in the registry!  These are all neatly stored for you in HKCR\Clsid\GUID Here\localserver32.  This last key is where you get the friendly name and then you can right click on the server and make the needed changes and all is right with the world again!

I have noticed that usually the name in the registry doesn’t match up perfectly with the DCOM server name, but you can usually make sense of it.  The one above is the reporting point on one of my SMS servers and it is stored as something like “SMSRPHost Class” and in localserver32 it shows up as “SMSRPH.exe”, in the registry.  I knew I was having issues where some of my Reporting Users could not get the page to load, and it logged the time and user name in the error, with all that I could determine what server needed to have local launch permissions.  I made the change and it started working right away.

Anthony Clendenen