If you follow this guide, your Windows 7 machine will scream with sub-15 second boot times from an NVMe drive. Just remember—with great speed comes great responsibility (and a lack of security updates).
While Microsoft provides a generic driver, many SSD manufacturers offer proprietary drivers that often provide better performance and stability on Windows 7. Installing Windows 7 on an m.2 NVMe drive? - Super User
Software like , FlashBoot Pro , or Gigabyte’s Windows USB Installation Tool automated slipstreaming USB 3.0 + NVMe drivers into a Windows 7 ISO. Suddenly, you could install Windows 7 on an NVMe drive without PS/2 keyboards or optical drives.