Use this setup preparation when you have intentionally chosen a clean installation and want its Windows and boot files to reside on one intended disk. The reports describe installation failures with several disks connected and an installation whose boot files depended on a different disk. An installation percentage alone does not prove this cause.
- Back up the target and other attached disks. Record each disk model and its role. A clean installation can erase the selected target; stop if its identity or intended data loss is unclear.
- Shut down, disconnect external power and follow the computer manufacturer’s service procedure to isolate the non-target disks. Do not remove a disk from a running computer.
- Start compatible official Windows installation media with only the intended target disk connected. Follow Microsoft’s clean-installation procedure for the supported release.
- Complete the first Windows startup with the other disks still disconnected.
- Shut down again before reconnecting the other disks. Keep the newly installed disk’s Windows Boot Manager as the intended firmware boot target.
Verify that the new installation boots independently and still starts after the other disks are reconnected. This establishes where its boot files reside. If removing another disk makes an existing installation unbootable, restore the recorded connections and inspect that boot dependency; do not erase the other disk or repeat installation blindly.