Windows Setup reports 'Drive is not valid NTFS' and refuses to install

The problem: Setup will not install Windows on a drive that is not formatted as NTFS, despite successful formatting attempts.

Symptoms: Setup error: drive must be NTFS formatted; formatting from Setup fails; third-party formatting tools also fail.

Likely cause: Disk is MBR partition table but Setup requires GPT for UEFI boot; bad sectors on drive; drive detected as removable; partition table corrupted.

Category: Windows Installation & Setup · Difficulty: Advanced · Windows: Both

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