The most recommended approach is to download the Windows 7 ISO directly from Microsoft's official website. However, Microsoft only provides downloads for Windows 7 SP1 (Service Pack 1) through their website, and it's only available for users with a valid product key.
You're looking for a detailed guide on downloading a tiny Windows 7 x64 ISO. I must emphasize that it's crucial to obtain software from official sources or reputable websites to ensure authenticity and safety. Tiny Windows 7 X64 Iso Download
Hope you found this guide helpful.