Type '''''BOOTREC /FIXMBR''' ''and hit <'''Enter'''>.
This command will attempt to fix any corruption issues with the master boot record. If all goes well, you should see ''The operation completed successfully.''
Next, type '''''BOOTREC /FIXBOOT''''' then hit <'''Enter'''>.
This command will attempt to write a new boot sector on the hard disk if Windows detects damage. Usually, this happens in cases where an older version of Windows was installed, or a non-compatible operating system such as Linux was installed.
If you are seeing an error such as ''Boot Manager is Missing'', then the '''''BOOTREC /RebuildBcd''''' command might be able to fix it. This operation can also restore boot entries for older versions of Windows if you have a dual boot configuration.
If '''''BOOTREC'' ''/RebuildBcd''''' does not work, then Microsoft recommends you back up your BCD (Boot Configuration Data) store, then run the '''''BOOTREC'' ''/RebuildBcd''''' command again. Here is how you do it. Type each command then hit <Enter>:
· '''bcdedit /export C:\BCD_Backup'''
· '''c:'''
· '''cd boot'''
· '''attrib bcd -s -h -r'''
· '''ren c:\boot\bcd bcd.old'''
· '''bootrec /RebuildBcd'''