I just used the media creation tool and the upgrade don't work, with the same result: missing operating system
The clean installation(from media creation) is ok, but windows 10 is not activated.
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The same here, I tried 3x without success, with the same message: missing operating system
Dell studio 1458 - i5 - 6gb ram - SSD (win 7 home premium >> win 10 home premium)
The windows 10...