Why does user NT AUTHORITY\LOCAL want to do a local launch of IPBusEnum?

Why does user NT AUTHORITY\LOCAL want to do a local launch of IPBusEnum?

I have Windows Vista Home Premium. A few months ago, I got a message on
boot-up that "Windows could not connect to the System Event Notification
Service" and that "This problem prevents standard users logging on to the
System". The message also suggested looking in the System Event viewer to
find the reason it occurred. Among various errors that I found was "The
application-specific permission settings do not grant Local Launch
permission for the COM Server application with CLSID
{C97FCC79-E628-407D-AE68-A06AD6D8B4D1} to the user NT AUTHORITY\LOCAL
SERVICE SID (S-1-5-19) from address LocalHost (Using LRPC). This security
permission can be modified using the Component Services administrative
tool."
I browsed the web and found many suggestions for "curing" the problem,
none of which gave satisfactory explanations as to why it occurred (and is
still occurring). I have found through the registry that the COM Server
application is IPBusEnum.
My questions are:
Why does NT AUTHORITY\LOCAL want to locally launch IPBusEnum?
Why does an apparently powerful user, NT AUTHORITY\LOCAL, need permission
to locally launch IPBusEnum?
Why, if it does not and never has had permission to do this, does Windows
now completely lock out non-Administrators from doing anything?
Could this be a virus or trojan? I am reluctant to grant this permission
without knowing the answers.