Question How to create an MBR/Boot loader on a Windows 10 laptop

[lafaki]

Hi!

I have a laptop with two disk bays, I have one hard disk with Windows 10 and another hard disk with data files.

The MBR/bootloader was initially installed in the data disk (as it was in position 0).
Now I need to replace it with a bigger disk.
When I remove it and try to start the laptop only with the Windows 10 disk, I get an error that it cannot boot from this disk/partition.

Is there any tool that I can use for booting the laptop and creating a new MBR/Bootloader on the Windows 10 disk?
That disk has the Windows 10 partition, an 800 MB recovery partition and one 100 MB partition to be used for the MBR/bootloader.
The Windows 10 disk is now in position 0.

Any help would be very much appreciated!!

Thanks in advance,
Akis

 

[SkyNetRising]

Can you show screenshot form Disk Management?

Tool to use is bcdboot.
First you create bootable partition, format it and then use bcdboot command to create bootloader files.

 

[TerryLaze]

EasyBCD is an easier version of the bcdtools,it's free for non commercial use.
Just boot into windows normally from the old data disc and then use easybcd to first create a MBR or UEFI bootloader it's IMPORTANT to choose the right one and then create a bcdstore on the windows 10 disc where you can the add windows as a boot menu item (although it should automatically boot into it)

 

[lafaki]

I cannot boot my laptop, the data disk with the boot loader has got corrupted some how. Now this disk is removed and I only have the Windows 10 disk that I cannot boot.

Is there any tool to boot with and use it for this purpose?

Can I boot with the abovementioned tools and get into a runtime environment for executing commands to create bootloader files?
I can make active my 100 MB partition in the Windows 10 disk using Microsoft DiskPart

 

[SkyNetRising]

Boot from windows 10 installation media.
Then perform bootloader repair commands.

diskpart​

list disk​

(select disk containing windows. If one disk present, then disk number is 0)​

select disk 0​

list partition​

(select 100MB system partition, partition number either 1, 2 or 3)​

select partition 3​

active​

assign letter=H​

list volume​

(determine volume label for windows partition, should be C: but can be some other letter also)​

exit​

bcdboot C:\windows /s H:​

​

Reboot into BIOS and set correct boot priority.
Done.

 

[lafaki]

I have followed the above instructions, all commands successfully executed.

I entered BIOS, I can only see my Windows hard disk as one entity (no volumes or partitions).

When I try to boot the laptop, I get the below error message:

"An operating system wasn't found. Try disconnecting any drives that don't contain an operating system. Press Ctrl+Alt+Del to restart"

 

[lafaki]

It finally worked when using the below commands

diskpart
list disk
(select disk containing windows. If one disk present, then disk number is 0)
select disk 0
list partition
(select 100MB system partition, partition number either 1, 2 or 3)
select partition 3
format
active
assign letter=H
list volume
(determine volume label for windows partition, should be C: but can be some other letter also)
exit
bcdboot C:\windows /s H: /f BIOS

I am not sure which of the two above changes made it work.

For the record, I also tried:
bootrec /fixmbr (executed successfully)
bootrec /fixboot (returned "Access is denied")
bootrec /rebuildbcd (returned "The Requested System Device Cannot Be Found")

THANKS ALL FOR YOUR HELP!