Windows7 Ultimate system startup "Missing operating system" how to do

Specific reason analysis:

Under normal circumstances, when the system boot record error occurs, the system boot record is located in the logic 0 fan The area is generated by the advanced formatting command FORMAT. Check whether the main boot partition table is correct. According to the starting address of the system partition indicated in the partition table, read the system boot record. If the read fails, the error message of “Error loading operating system” is displayed. The system boot record, the main boot program will check whether the last two bytes of the system boot record is 55AA, if not these two bytes, will give a "Missing operation system" prompt. This problem can be solved by simply using NDD. The specific steps are as follows.

1. First, re-partitioning the win7 system, it is estimated to be 0 track error, because 0 track can be used for booting, 255 track can also be used for booting, so be sure to divide the partition or hide the partition first when partitioning. The primary partition is at the end;

2, then the system must start the three necessary files: MSDOS.SYS, IO.SYS and COMMAND.COM, you can use the system recovery disk to enter the command prompt window, copy Enter the system disk and type the following commands in sequence.

copy MSDOS.SYS C:

copy IO.SYS C:

copy COMMAND.COM C

3, if unsuccessful, use The FORMAT C:/S command rewrites the DOS boot record. If the problem persists, it can be solved by reinstalling the system.