Download Windows 7 Disc Images (ISO Files).If you do not already have the Windows 7 or 10 ISO file, start by downloading one of them: The following post will walk you through the necessary steps to create a bootable Windows 7 or 10 USB drive from a modern Linux distribution.
However, many of those guides have missing steps, involve using Windows, or use programs not readily available on modern Linux distributions. There are a lot of guides on the web describing how to create a bootable Windows 7 or 10 USB drive in Linux.