I received the following error when trying to install the SNMP service on Windows Server 2008:
Attempt to install SNMP Service failed. The source for the specified package or file was not found (error value: 0x800F081F).
The solution was to install the System Update Readiness tool for the appropriate version of Windows. I recommend the manual install (method 2) here:
After hotfix 947821 is installed just try installing the failing feature or role again. In my case an incomplete Windows update or feature installation was preventing the installation of the SNMP feature.