Disk Partition Table and data recovery

The current hard disk capacity is getting bigger and bigger, transmission is getting faster and faster, and the price is getting cheaper, but there is not much improvement in security and reliability. Maybe it suddenly tells you that there is a bad track on the hard disk, the data you saved on the hard disk is also "one-stop", let alone the damage caused by accidental deletion, formatting, and other incorrect operations and viruses. Therefore, data backup and recovery are particularly important.
I. Hard Disk Partition Table and data recovery
If the hard disk cannot be detected on the computer, check whether the connection between the hard disk drive and the hard disk controller is normal and whether the power cord of the hard disk drive is normal; if multiple devices exist, check whether there is a conflict between hard disks or CDROM or other devices, or whether the master-slave relationship between devices does not match; check whether the hard disk information in CMOS is correct. If the fault works properly, it indicates that the fault has nothing to do with the hard disk. Otherwise, your hard disk may have been damaged.
Important configuration information of the hard disk, such as the Master Boot Record and fat table, may be damaged by viruses or data loss caused by sudden power failure or abnormal shutdown. If the system cannot be started from the hard disk but can be started from the floppy disk, you can try to access the hard disk after the floppy disk is started. If you can access the hard disk, it means that the operating system may be damaged, you can reinstall the operating system or directly connect the hard disk to another computer to back up the data. If you cannot access the hard disk, it may be that the boot area of the primary boot area or the boot area of the bootable partition is damaged. In this case, we can use tools such as debug to check whether the boot area of the hard disk is normal, or use the fdisk/MBR command to recreate Code If the hard disk has a boot virus, this command can also clear the virus. If you still cannot access the primary boot area, the hardware fault may occur on the hard disk, but it cannot be easily repaired using software.
It should be noted that a powerful restoration tool cannot restore all data in a hundred percent. Therefore, backing up data is not only a good habit, but also necessary for data security. In addition, the frequent use of anti-virus software is also a very good measure, and it is necessary to update the virus database from time to deal with the latest viruses. The following describes how to use kv3000, a popular anti-virus software, to Repair Disk Data.

1. Back up the correct Disk Master Boot Information
When the hard disk can be started, we should back up the boot information of the hard disk master to prevent unexpected events.
The command format is as follows:
Kv3000/B; kv3000/hdpt. dat
This command backs up a virus-free Master Boot information file on disk A, named hdpt. dat and hfboot. dat respectively. When the hard disk's primary boot information is damaged by viruses or the primary Boot Record is damaged, the "kv3000/A: \ hdpt. the dat command format is restored to a damaged hard disk, which can solve most of the damage to the Master Boot information and the failure to start the system.

2. Fixed the boot information of the hard disk master.
After booting the system with a floppy disk, run kv3000 and press the F6 key to check the hidden sector of the hard disk that cannot be booted. That is, check whether the boot information of the 0-disk, 0-column, and 1-sector on the hard disk is normal. The Master Boot information is the starting point of the hard disk boot. It is important to have two indicators, namely, 80 h and 55aa. 80 h is usually at the 1be offset. 80 indicates that the partition is activated, indicating that the system can be guided, and the entire Partition Table can only have one 80 h mark; the other is the 55aa mark at the end, it indicates that the Master Boot information is a valid record. In addition, the boot information of each partition is also ended with 55a. If no key code is found in the 0-side, 0-column, and 1-sector of the hard disk, the hard disk itself cannot be self-guided, that is, it cannot enter the hard disk after being guided by a floppy disk. You can find it in the hidden sector of the hard disk. After finding it, the system will automatically display the red "80" and "55aa" Flashing in the table, with a sound to remind you, "F9 = save to side 0 cylinder 0 Sector 1" is displayed at the bottom of the screen !!! ". At this time, press the "F9" key to overwrite the primary boot information of the original hard disk to the zero-sector, zero-sector, and one-sector. Then, the computer will reboot the hard disk, recover the boot performance of the hard disk, and access the hard disk after the boot from the floppy disk.

3. Fast rebuilding of the hard disk partition table
As a result of virus damage or operation errors, the hard disk master boot records and partition tables are damaged. When the hard disk cannot be booted or the disk cannot be booted into the hard disk, if the Master Boot Record is backed up on a floppy disk with the kv3000/B command, kv3000/hdpt can be used. the dat command then restores the Master Boot Record of the hard disk. If you have not previously backed up the boot information of the hard disk master, you only need to use the kv3000 function to quickly recreate the hard disk partition table.
After the floppy disk boots the system, run kv3000 and press the "F10" key to quickly test system parameters and hard disk partition tables. If the hard disk partition table is abnormal, kv3000 will prompt you to save the bad partition table to a floppy disk first, in case the operation fails, and then re-create the hard disk partition table automatically to bring the hard disk back to life.
If the hard disk has only one partition (which is rare now), and the file allocation table (fat table) and file root directory table (root table) have been severely damaged by viruses, therefore, even if the Partition Table of the C disk is restored, the C disk cannot be booted. You must manually use other dedicated repair software to restore the data. However, if there are other extended partitions, such as D and E, kv3000 can normally retrieve the undamaged partition, recreate a new hard disk primary partition table, and then use the DOS system floppy disk to guide the computer, you can enter the D, E, and other partitions of the hard disk.

4. Recover Hard Disk Data
The data in the directory partition and the fat file allocation table on the primary partition (C :) may be partially or entirely damaged, although the file information is not completely damaged, however, it is difficult to completely restore the database. By using software such as Norton NDD, you can restore the link of the file data, but it is impossible to restore it completely, that is, the data cannot be completely composed of meaningful files. After the restoration, if the data in the directory and FAT file allocation table is not completely damaged, some files will be completely saved, and some retrieved files may be lost or combined into a large file.