This question seeks to understand your knowledge of older operating systems. Many technical support engineers, especially those who recently graduated from a formal education or tech school, are more familiar with the most current operating systems, hardware, and applications than older versions of these. However, many organizations still use legacy systems and software in their IT infrastructure. A senior technical support engineer needs to be familiar with a wide variety of IT assets. As with any question, if you're not familiar with this, admit it and then describe how you would go about acquiring the information you need to answer the question.