Final answer:
Hewlett-Packard differentiates itself by offering product support services, specifically through a help line that aids in troubleshooting and customer assistance, which enhances customer satisfaction and builds loyalty.
Step-by-step explanation:
When Hewlett-Packard offers a help line for computer questions and problems, it is providing additional value to their product through a customer service-oriented approach. This inclusion certainly improves the perceived level of quality of HP's products by ensuring that customers have access to support if they encounter any issues.
However, more specifically, it is categorized as product support services because it is a post-purchase service aimed at helping customers use and troubleshoot the product effectively. The help line adds to HP's competitive advantage by providing direct, potentially real-time assistance to consumers, thereby improving customer satisfaction and loyalty.