dcomlaunch - Necessary
DCOMLaunch was added with Service Pack2.
"To reduce the attack surface of Windows and provide defense in depth, the RPCSS service functionality was split into two services. The RPCSS service with all the original functionality that did not require Local System privileges now runs under the Network Service account. A new DCOMLaunch service that includes functionality that requires Local System privileges runs under the Local System account.
This change reduces the attack surface and provides defense in depth for the RPCSS service since an elevation of privilege in the RPCSS service will now be limited to the Network Service privilege."