Final answer:
Lenovo Diagnostics is the diagnostic tool that supports all Lenovo PCs, designed for a broad range of system checks on hardware components.
Step-by-step explanation:
The diagnostic tool that supports all Lenovo PCs is Lenovo Diagnostics. This tool is designed to test various components of Lenovo computers to ensure proper functionality. While Lenovo Solution Center was an earlier tool used for diagnostics and support, it has been replaced by Lenovo Vantage and Lenovo Diagnostics. Lenovo Vantage is typically used for devices running Windows 10 and offers device-specific customizations and updates, but it is Lenovo Diagnostics that stands as the comprehensive diagnostic tool made to support all Lenovo PCs, offering a wide range of system checks for hardware components. Lastly, Lenovo Companion was an older support application that has been integrated into Lenovo Vantage.