This article explains how you can recover the bootloader for the following Windows versions: Windows Vista, Windows 7, Windows 8, and Windows 10 using the setup DVD (installation DVD). If you don&#…
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If you don't have installation media but you have access to another W10 PC, you can create a repair disc which will do the same job following the instructions in the above link.
Control Panel > Backup & Recovery > Create Repair Disc
Failing either of those options you can use Neosmart's bootable repair system