: Many unofficial "preactivated" ISOs are laced with malware, such as Trojan.Clipper.231 , which can steal cryptocurrency or sensitive login information.

This is legitimate. It means the ISO is configured to detect the embedded OEM license key in your HP laptop or desktop motherboard, activating automatically upon installation.

Connect your computer to the internet once the installation finishes.

for automatic activation.

Complete the installation. Once you reach the desktop and connect to the internet, your HP hardware will activate automatically. Finding HP Specific Drivers

The only safe, secure, and legal way to obtain the Windows 10 Pro ISO file is directly from Microsoft's official website: