Microsoft no longer provides direct downloads for Windows 7 ISO files. However, you can still obtain a copy from various sources:
Open Rufus, select your USB drive, and then click "Select" to locate your Win 7 ISO. win 7 iso file download
was historically a safe wrapper around Microsoft’s own servers, but Microsoft later restricted access. Current functionality may be limited. Microsoft no longer provides direct downloads for Windows
This is the industry-standard tool for creating bootable USB drives. select your USB drive