Private _TextFound As Boolean = False
Private Sub Button10_Click(sender As System.Object, e As System.EventArgs) Handles Button10.Click
    FindTheText("C:tempInHere", "cheese")
    MessageBox.Show(_TextFound)
End Sub

Private Sub FindTheText(sDirToLookIn As String, sTextToFind As String)
    If IO.Directory.Exists(sDirToLookIn) Then
        Dim di As New IO.DirectoryInfo(sDirToLookIn)
        For Each dii As IO.DirectoryInfo In di.GetDirectories
            FindTheText(dii.FullName, sTextToFind)
        Next
        If IO.File.Exists(sDirToLookIn & "SomeFile.html") Then
            If IO.File.OpenText(sDirToLookIn & "SomeFile.html").ReadToEnd.Contains(sTextToFind) Then
                _TextFound = True
            End If
        End If
    End If
End Sub