If you've downloaded an hfl.7z file, you'll need a modern archiver to see what's inside:
Data archivists prefer the .7z extension over standard .zip because it uses the LZMA algorithm , which can achieve 30-50% better compression than traditional methods. This makes it perfect for sharing massive game libraries or preserving rare software without eating up terabytes of bandwidth. hfl.7z
Original "WON" versions of Half-Life (v1.1.1.0) that don't require Steam to run. If you've downloaded an hfl