Several ways to save the hard drive

This type of failure is more common, that is, from the hard disk can not start, starting from a disk can not enter the C disk, the use of the CMOS automatic monitoring function can not find the existence of the hard disk. Most of this fault occurs in the connection cable or IDE port, the hard disk itself failure rate is very small, can be replaced by reseating the hard drive cable or change the IDE port and cable, etc. to replace the test, you can quickly find fault. If the new hard drive is not recognized, there is a common reason for the main line on the hard disk, if the hard disk is connected to the IDE's primary disk, the hard drive must be the main disk, the jumper error is generally unable to detect the hard disk

2, CMOS caused by the fault

Whether the CMOS is correct or not directly affects the normal use of the hard disk, mainly refers to the type of hard disk. Fortunately, the machine now supports the "http://www.aliyun.com/zixun/aggregation/16658.html" >ideautodetect function, can automatically detect the type of hard disk. This feature is used to reset the type after a new hard drive is connected or a new hard drive is replaced. Of course, there are now types of motherboards that can automatically identify the type of hard disk. When the hard disk type is wrong, sometimes it is impossible to start the system, sometimes it can start, but read and write errors occur. For example, the hard disk type in CMOS is less than the actual hard disk capacity, then the sectors behind the hard disk will be unable to read and write, and the individual partitions will be lost if they are multiple partition states. There is also an important cause of failure, because the current IDE supports the logical parameter type, the hard disk can be used normal,lba,large and so on. If you install the data in a normal mode, and then change to another mode in the CMOS, you will have a hard drive reading and writing error, because its physical geology mapping relationship has changed, will not be able to read the original correct hard disk location.

3. Boot failure caused by the main boot program

The main boot sector of the hard disk is one of the most sensitive parts of the hard disk, and the main boot program is part of it, which is used primarily to detect the correctness of hard disk partitions and to determine the active partition, which is responsible for handing over the boot to the DOS or other operating system of the active partition. This piece of program corruption will not boot from the hard drive, but can read and write to the hard drive from the soft zone or the light area. The easiest way to fix this failure is to use a high version of DOS for FDISK, which will replace (override) the hard drive's main boot program directly when you run with the parameter/mbr. In fact, the main boot sector of the hard disk was created by this program, and the Fdisk.exe included a complete hard drive master boot program. Although the DOS version is constantly updated, the main boot of the hard drive has not changed from dos3.x to the current Windos95 dos, so just find a DOS boot disk boot system and run the program to fix it. In addition, other tool software like kv300 has this feature.

4, partition table error-guided boot failure

The partition table error is a serious error on the hard drive, and the degree of error can cause different losses. If there is no active partition flag, the computer cannot start. However, you can read and write to the hard disk after booting the system from a soft zone or a light area, and you can repair it by using the Fdisk reset active partition. If it is a partition type error, you can cause a partition to be lost. The fourth byte of the partition table is the partition type value, and the normal bootable 32MB primary DOS partition value is 06, while the Extended DOS partition value is 05. If you change the basic DOS partition type to 05, you cannot start the system, and you cannot read or write data from it. If you change the 06 to DOS unrecognized type such as EFH, DOS thinks the partition is not DOS partition, of course, can not read and write. Many people use this type of value to implement a single partition of encryption technology, restore the original correct type value to make the partition back to normal. Other data in the partition table is used to record the starting or ending address of the partition. Damage to this data will cause confusion or loss of the partition. It is generally not possible to manually recover, the only way is to use the Backup partition table data to write back, or from the other same type and partition status of the same hard drive to get the partition table data, otherwise will cause other data permanent loss. In the operation of the main boot sector, NU and other tools can be used, the operation is very convenient, can directly to the hard disk main boot sector to read or write or edit. Of course, debug can also be used, but the operation is cumbersome and has a certain risk.
5, the partition valid mark error caused by the hard disk failure