This is normal when installing High Sierra on HDDs. Wait up to 2 hours. The transition from HFS+ to APFS slows the process.

If you cannot access the official App Store installer because you are on Windows or a Chromebook, you are forced into the dangerous waters of third-party hosting. If you go that route, use a reputable torrent with many seeders and against known good values (search: High Sierra 10.13.6 ISO SHA1 ).

Practical recommendations

: You can find macOS High Sierra in the Mac App Store .

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