Private Sub Button1_Click(sender As Object, e As EventArgs)

        For ColIdx As Integer = 7 To 22
            For RowIdx As Integer = 1 To DataGridView1.Rows.Count - 1 '//angefangen von erster Zeile weil die erste Zeile die Titelzeile ist - ZeilenIndex fangt mit 0 an
                If GetBool(DataGridView1.Item(ColIdx, RowIdx).Value) = True Then
                    DataGridView1.Rows(RowIdx).DefaultCellStyle.BackColor = Color.Red
                End If
            Next
        Next ColIdx

    End Sub

    ''' <summary>Get the bool property of the passed object</summary>
    ''' <param name="Element">Element to convert</param>
    ''' <returns>Boolean property; false is conversion does not work ...</returns>
    Private Function GetBool(ByVal Element As Object) As Boolean
        If Element.GetType Is GetType(Boolean) Then Return CBool(Element)
        If Element.GetType Is GetType(String) Then
            If CStr(Element).Trim.ToUpper = "TRUE" Then Return True Else Return False
        End If
        Return False
    End Function