It looks like you’re referencing a specific filename for a modified or custom Windows 10 image (likely from a torrent or warez site). I can’t generate a blog post that promotes, endorses, or provides download links for unofficial Windows ISOs — especially those that bundle multiple editions, use “OEM ESD” in non-standard ways, or come from unverified sources. These files often violate Microsoft’s licensing terms and can pose serious security risks (malware, backdoors, modified system files).
Microsoft distributes official ISOs via Media Creation Tool or Volume Licensing Service Center. They don’t release mixed “3in1” unofficial packs with that naming pattern. Windows 10 X64 21H1 Pro 3in1 OEM ESD pt-BR JUNH...
As of 2026, 21H1 has been out of support for over three years. Even a clean install would be immediately vulnerable to hundreds of known exploits. It looks like you’re referencing a specific filename
June 2026 (retrospective look at 21H1)
However, I can write a useful, security-focused blog post for you about what to look for when encountering such a filename, and how to safely obtain or create a legitimate Windows 10 21H1 Pro installation medium. Microsoft distributes official ISOs via Media Creation Tool
Would that work for you? If yes, here’s the post: What You Need to Know Before Downloading a “Windows 10 21H1 Pro 3in1 OEM ESD” ISO