Fix the MBR in Windows 10
You need the first Windows 10 establishment DVD to fix the Master boot record. On the off chance that you don't have the Windows 10 establishment DVD to run Command Prompt, go to Fix MBR with Easy Recovery Essentials.
The directions are:
1.Boot from the first establishment DVD (or the recuperation USB)
2.At the Welcome screen, click Repair your PC
3.Choose Troubleshoot
4.Choose Command Prompt
5.When the Command Prompt burdens, type the accompanying directions:
bootrec/FixMbr
bootrec/FixBoot
bootrec/ScanOs
bootrec/RebuildBcd
6.Press Enter after each direction and trust that every task will wrap up
7.Remove the DVD from the plate
8.Type exit
9.Hit Enter
10.Restart your PC and check if Windows 8/8.1 would now be able to boot.
On the off chance that bootrec utility doesn't fix your Windows 8/8.1, have a go at following the following directions to fix the EFI bootloader of the Windows 8/8.1:
1.Boot from the establishment DVD or the Windows 8 or Windows 8.1 recuperation USB
2.Click Repair your PC
3.Choose Troubleshoot
4.Choose Command Prompt
5.Type these directions all together and hit Enter after each:
diskpart
sel circle 0
list vol
These directions will choose the principal plate of your PC and the rundown every one of the parcels accessible on that circle.
6.Check for the volume thing that has the Fs segment FAT32. The EFI segment must be designed under FAT32.
In the event that the volume number of EFI parcel is "2", type the accompanying direction: sel vol 2
In the event that the volume number is unique in relation to 2, supplant "2" with the number accessible on your PC.
7.Assign a letter to this parcel, a letter that is distinctive that those effectively accessible on your PC, for instance x:\.
8.Type this order to allot the letter:
allot letter=x:
9.Wait for the achievement message to show up:
DiskPart effectively alloted the drive letter or mount point.
10.Type exit to stop the DiskPart utility:
exit
Type this order and supplant x:\ with the letter you relegated before to the EFI segment:
disc/d x:\EFI\Microsoft\Boot\
11.Then sort the bootrec order to fix the volume:
bootrec/fixboot
12.Now you have to reinforcement the old BCD and reproduce another one. Type:
ren BCD BCD.backup
13.Type this order to reproduce the BCD and supplant the x:\ with the alloted letter prior:
bcdboot c:\Windows/l en-us/s x:/f ALL
14.In above order, Windows is introduced on c:\. In the event that the drive letter where your Windows 8/8.1 is introduced is extraordinary, supplant c:\ with your drive letter.
15.Remove the DVD from the plate
16.Type exit
17.Restart your PC