Have just upgraded my Windows 2000 Server, running Exchange 2003, to Windows 2003 and now having the following problems with Exchange;
When I try to access OWA get error message HTTP/1.1 503 Service Unavailable.
Lots of errors in the event log regarding;
Initialization of external interface OLEDB failed; Error Unknown error. and
Access denied attempting to launch a DCOM Server. The server is:
The user is SYSTEM/NT AUTHORITY, SID=S-1-5-18.
Have tried the MS KB article KB305030 but no help.