[Jaytee Bushwacker]

Here is the code I use in my app to create a thread and do the backup/clear operations. It took a couple days but I finally have it working pretty well for the local connection, I can make it work for remotes but I'm trying to decide how I want to design my connection function to accept a username/password.

 Private Sub cmdWMIArchive_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdWMIArchive.Click
        Dim saveFileName As String = Me.archiveDrive & "" & Me.archiveRootDirectory & "" & Me.txtSaveFile.Text
        Dim computer As String = Me.txtComputerName.Text
        Dim args(1) As Object
        args(0) = saveFileName
        args(1) = computer
        Me.rtbStatus.Clear()

        'BackupAndClearLog(args)
        Dim threadA As New Thread(New ParameterizedThreadStart(AddressOf backupClearLog))
        threadA.Start(args)

        
    End Sub


    Sub backupClearLog(ByVal args As Object)

        Dim scope As New System.Management.ManagementScope
        Dim logSearcher As New System.Management.ManagementObjectSearcher
        Dim logfiles As System.Management.ManagementObjectCollection
        Dim logfile As System.Management.ManagementObject

        Dim inParams As System.Management.ManagementBaseObject
        Dim outParams As System.Management.ManagementBaseObject

        Dim result As UInt32
        Dim backupFile As String = args(0)
        Dim computer As String = args(1)

        Dim updateArgs(1) As Object

        Try

	    'My attempt at creating a dll with WMI functions 
            'it just executes the following manual way code
            myWMI.openConnection(scope, computer)
            
            'The Manual way
            'scope.Options.EnablePrivileges = True
            'scope.Path.Path = "\\.\root\cimv2"
            'scope.Connect()

            'I'm calling a sub that updates a richtextbox control on my UI with connection status
            Me.Invoke(New connectedToDelegate(AddressOf connectedTo), scope)
            logSearcher.Query.QueryString = "Select * from win32_NTEventLogFile WHERE LogFileName='security'"
            logfiles = logSearcher.Get()

            For Each logfile In logfiles
                'Can't update UI from a thread directly next few lines do it via invoke                
                'rtbStatus.AppendText(logfile.Item("Name") & ControlChars.Cr)
                
                updateArgs(0) = False
                updateArgs(1) = logfile.Item("Name") & ControlChars.Cr
                Me.Invoke(New updateStatusDelegate(AddressOf updateStatus), updateArgs)

                'This block actually does the backup
                inParams = logfile.GetMethodParameters("BackupEventLog")
                inParams.Item("ArchiveFileName") = backupFile
                outParams = logfile.InvokeMethod("BackupEventLog", inParams, Nothing)
                result = outParams.Item("returnValue")

                'Can't update UI from a thread directly next few lines do it via invoke                
                'Me.rtbStatus.AppendText("BackupEventLog " & myWMI.exitCodeMessage(outParams.Item("returnValue"), "win32_NTEventLogFile") & ControlChars.Cr)
                
                updateArgs(0) = False
                updateArgs(1) = "BackupEventLog " & myWMI.exitCodeMessage(outParams.Item("returnValue"), "win32_NTEventLogFile") & ControlChars.Cr
                Me.Invoke(New updateStatusDelegate(AddressOf updateStatus), updateArgs)

                'If backup was successful result will be 0 - only then do we clear
                If result = 0 Then
                    'Have to do the same thing as backup to clear the log just call the ClearEventLog method
                    'There are no parameters for the clear method but if we don't reinit inParams it will hose up
                    inParams = logfile.GetMethodParameters("ClearEventLog")
                    outParams = logfile.InvokeMethod("ClearEventLog", inParams, Nothing)

                    'Can't update UI from a thread directly next few lines do it via invoke                
                    'Me.rtbStatus.AppendText("ClearEventLog " & myWMI.exitCodeMessage(outParams.Item("returnValue"), "win32_NTEventLogFile") & ControlChars.Cr)
                    updateArgs(0) = False
                    updateArgs(1) = "BackupEventLog " & myWMI.exitCodeMessage(outParams.Item("returnValue"), "win32_NTEventLogFile") & ControlChars.Cr
                    Me.Invoke(New updateStatusDelegate(AddressOf updateStatus), updateArgs)

                End If
            Next
        Catch ex As Exception
            'Can't update UI from a thread directly next few lines do it via invoke                
            'Me.rtbStatus.AppendText(ex.Message & ControlChars.Cr)
            updateArgs(0) = False
            updateArgs(1) = ex.Message & ControlChars.Cr
            Me.Invoke(New updateStatusDelegate(AddressOf updateStatus), updateArgs)

        End Try
    End Sub