Win7 system ntldr is missing file how to do

1, when the computer hard disk information has been tampered with, that is, the system can not find the hard disk, can not find the system file in the system partition, you can enter the Win7 system BIOS panel, then Find the Standard CMOS Setup item and set the hard drive to Auto.
2, under the Win7 system, set the system active partition, find an MS-DOS toolbox CD, then run Fdisk, and then select 2 (Set active partition) for system partition activation.
3, if you still can not operate, it may be because the main boot record in the Win7 system hard disk partition is destroyed, so can not find the system partition, then you can only run FDISK /MBR under the MS-DOS toolbox.