If you are installing it on a modern SSD with a fast CPU, you are fighting uphill. Windows 7 lacks native drivers for NVMe, USB 3.1, and modern Wi-Fi chips. Even if you get past this error, you will likely face more driver issues later.

The most common cause, and the easiest to fix, is the installation media itself. Windows 7 is old, and if you downloaded an ISO file from the internet, it might have been corrupted during the download, or the file transfer to the USB drive encountered errors.

This is the most critical scenario. The error often appears stuck at 0% or a low percentage.