Hello there!
This is quite an old thread here, and there have been many changes and fixes in the meantime. But here is the latest status:
HP warranty
The HP Warranty API is a RESTful programmatic interface that provides warranty information about HP devices. It is designed for HP's enterprise customers to check the warranty status of their fleet of HP devices. However, the HP Warranty API is currently not available for IT service companies and third-party ISVs that need to check warranty information for their customers' devices. As a result, at this time, Lansweeper is unable to retrieve HP warranty information.
Dell warranty
Fully functional in the latest version of Lansweeper.