Basically, SNMP Informant extends the Microsoft SNMP service by adding additional OIDs that can be read thus providing additional details about the Windows system.
From: Adam Armstrong <adama@memetic.org> To: Observium Network Observation System <observium@observium.org> Sent: Tuesday, May 7, 2013 8:34 AM Subject: Re: [Observium] Support for SNMP Informant on Windows?