The command in Windows 8/8.1/10 for fixing MBR is "bootsect.exe".

bootsect /nt60 drive_letter: /mbr

this fixes boot record of partition mapped to "drive_letter:" and the MBR of the disk where the partition is placed.

C:\Windows\system32>bootsect

bootsect {/help|/nt60|/nt52} {SYS|ALL|<DriveLetter>:} [/force] [/mbr]

Boot sector restoration tool

Bootsect.exe updates the master boot code for hard disk partitions in order to
switch between BOOTMGR and NTLDR.  You can use this tool to restore the boot
sector on your computer.

Run "bootsect /help" for detailed usage instructions.

Alternatively you can use "Dual-boot Repair Tool" which has a graphical interface to bcdboot.exe, bootsect.exe and other useful functions like boot sector view and ... one click dual-boot repair function for Windows 10/8/7/Vista (also can fix Windows XP boot files).

This is a very common question seen on Stackoverflow.

The important part here is not the command displayed in the error, but what the actual error tells you instead.

a Quick breakdown on why this error is received.

cmd.exe Being a terminal window relies on input and system Environment variables, in order to perform what you request it to do. it does NOT know the location of everything and it also does not know when to distinguish between commands or executable names which are separated by whitespace like space and tab or commands with whitespace as switch variables.

How do I fix this:

When Actual Command/executable fails

First we make sure, is the executable actually installed? If yes, continue with the rest, if not, install it first.

If you have any executable which you are attempting to run from cmd.exe then you need to tell cmd.exe where this file is located. There are 2 ways of doing this.

1. specify the full path to the file.

   "C:\My_Files\mycommand.exe"

2. Add the location of the file to your environment Variables.

Goto:

------> Control Panel-> System-> Advanced System Settings->Environment Variables

In the System Variables Window, locate path and select edit

Now simply add your path to the end of the string, seperated by a semicolon ; as:

;C:\My_Files\

Save the changes and exit. You need to make sure that ANY cmd.exe windows you had open are then closed and re-opened to allow it to re-import the environment variables. Now you should be able to run mycommand.exe from any path, within cmd.exe as the environment is aware of the path to it.

When C:\Program or Similar fails

This is a very simple error. Each string after a white space is seen as a different command in cmd.exe terminal, you simply have to enclose the entire path in double quotes in order for cmd.exe to see it as a single string, and not separate commands.

So to execute C:\Program Files\My-App\Mobile.exe simply run as:

"C:\Program Files\My-App\Mobile.exe"

Your Path environment variable doesn't contain C:\Windows\System32. Please try adding it and your error will be resolved!