The value of 'hrSWInstalledIndex' corresponding to the first
associated conceptual row in the 'hrSWInstalledTable' of the
Host Resources MIB (RFC 2790) and an (optional) associated row
in 'xcmHrSWInstalledTable' in XCMI Ext to Host Resources MIB,
or zero if none.
Usage: A 'chain' of one or more Software Installed entries in
the Host Resources MIB MAY be associated with a service.
By convention, the FIRST of these entries SHALL represent
the security functional unit of a service.