Since you have both Windows 8.1 and Kali Linux installed. The Windows Boot Manager could work but it is very fiddly and mysterious in 8.1.
https://askleo.com/how_do_i_boot_from_cddvdusb_in_windows_8/ http://www.healthcarereportcards.com/how-to-fix-mbr-windows-81-without-cd.html https://ja.wikipedia.org/wiki/PowerShell https://www.howtoguides.org/fix-MBR-in-Windows-7 https://www.howtoguides.org/Fix-bootmgr-is-Missing-in-Windows How to Fix Boot Records in Windows Using Command Prompt For Windows 8 or 8.1 users need to launch Command Prompt either from the Advanced options or from the Safe Mode Interface. And after launching the Command Prompt type bootrec.exe and hit Enter. You will get four parameters: /FixMbr, /FixBoot, /ScanOs and /RebuildBcd. Now know how each of these parameters helps to solve the boot problems. Well, the Bootrec.exe tool can handle most boot issues, but it may happen that it does not fix every possible scenario occur in Windows PC.
https://windowstechies.com/fix-boot-record-issues-with-command-prompt/ https://windows101tricks.com/repair-rebuild-master-boot-record-mbr-windows-10/ https://www.lifewire.com/fixboot-command-2625886 https://www.backup-utility.com/backup-restore/windows-automatic-repair-loop.html https://www.sevenforums.com/general-discussion/17521-how-fix-mbr-through-command-prompt.html
Create Bootable USB Flash Drive to Install Windows 10… Clear clean and easy to understand, thank you Shawn great tutorial, making my USB flash drive shortly Fix UEFI Boot: Repair UEFI Boot in Windows 10/8/7 – EaseUS This article provides effective methods and detail guide for you to fix computer UEFI boot for Windows 10/8/7 with ease. If you are having problems with UEFI bootloader and fail to boot your Windows 10/8/7 system, follow to find a solution… Fix for Master Boot Record of This Hard Drive Is Damaged | MBR… To fix the problem of Master Boot Record of this hard drive is damaged, follow the tips and solutions in this post, which have helped many people repair damaged or corrupted MBR on a hard drive, external hard drive, USB flash drive and…
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Windows 8.1 MBR accidently deleted HELP - Microsoft Community
