Help with progressbar and counter label

[Darkmatter5]

here's my code:

Private Sub btnBeginScan_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBeginScan.Click
        Dim db As New byrndbDataContext

        For Each pdffile In strPDFFiles
            strImagesScanned += 1
            pbScan.Value += 1
            lbImagesScanned.Text = strImagesScanned
            Dim info As New FileInfo(pdffile)
        Next
        For Each tiffile In strTIFFiles
            strImagesScanned += 1
            pbScan.Value += 1
            lbImagesScanned.Text = strImagesScanned
            Dim info As New FileInfo(tiffile)
        Next

        lbNewImages.Text = strNewImages
    End Sub

The progressbar runs perfectly, but the lbImagesScanned.Text isn't updated until all the scans are completed. Please advice.