Ran into this issue working with SNMP services.  When installing SNMP Services on a Windows 2003 SP2 standard (not enterprise) server.  The SNMP installation stops three processes without any notification to the user  before completing.  The SQL Server Process, The SQL Server Agent Process and the Remote Access Connection Manager process.  This only happens in this instance of Windows.  After installation SNMP Services starts automatically but the other three services will remain stopped.  Nice "feature".