Consider using it in an "Air-Gapped" (offline) environment if possible.
Use (free, open-source, and trusted):
Regardless of where you download, verify the file hash. A legitimate Windows 7 64-bit ISO (with SP1) will have a specific SHA-1 value. windows 7 64-bit iso file download
Finding a reliable in 2026 is a bit like digital archaeology. Since Microsoft officially ended support in 2020 and removed direct download links from their main site, users now have to rely on alternative (but still legal) repositories. 💿 Where to Download (2026 Sources) Consider using it in an "Air-Gapped" (offline) environment
Before you burn that ISO to a USB drive (using Rufus, not the Windows 7 USB tool, which fails on UEFI systems), you need to know the hard truths about installing Windows 7 in 2024: not the Windows 7 USB tool