Graphic pc challenging disk repair and data recovery

3.five Really hard Disk Unlocking three.five.1 Challenging Disk Locking Principle Tough disk locking is normally associated to the partition table on the really hard disk, so you need to very first recognize the partition table of your really hard disk. The tough disk partition table is located in the 0 cylinder 0 head 1 area. Extra than 200 bytes in the front of this sector are the main boot plan, as well as the following 64 bytes from O1BEH would be the partition table. The partition table features a total of 64 bytes and is divided into 4 columns, each with 16 bytes, made use of to describe a partition. If it is actually partitioned with DOS's Fdisk plan, only a maximum of two columns are made use of. The very first column describes the basic DOS partition, along with the second column describes the extended DOS partition. The structure from the column from the partition table along with the meaning of each and every byte are as follows: (1) OOH: mark the active byte, the active DOS partition is 80H, and the other is 00H; (two) 01H: the head quantity with the logical 0 sector of this partition; (three) 02H: the sector number within the cylinder exactly where the logic 0 sector is positioned; (four) 03H: logic. The cylinder number where the sector is positioned; (5) 04H: partition sort flag; (six) 05H: head quantity from the last sector on the partition; (7) 06H: sector number with the last sector; (8) 07H: The cylinder number of the last cylinder; (9) 08H: the total quantity of sectors on the really hard disk ahead of this partition, expressed by Shuangyu; (1b) OCH: the total quantity of sectors in this partition, counted from logical 0 sectors, not Consists of hidden sectors, expressed in double words. The final two bytes of your partition table are valid signs of your partition table. For how to recover partition table in windows 10 who modify it, you might not be capable of boot from the really hard disk. This can be a simple process of locking the challenging disk. The option would be to boot in the floppy disk, the hard disk can still be utilised right after booting. Make use of the Diskedit software in Debug or Norton to restore the logo in the partition table of the difficult disk, and it really is no difficulty to boot from the difficult disk. A different way to lock the tough disk should be to modify the partition parameters. When how to recover hard drive partition table are all changed to 0, the partition can't be identified at startup, the tough disk can't be started, plus the hard disk is not recognized soon after booting from the floppy disk. Should you enter a drive letter C and press Enter, a prompt will appear: Invaliddriverspecification

At this time, since the personal computer is began along with the really hard disk will not be recognized, the contents of your hard disk 0 cylinder 0 head 1 sector can nevertheless be study out by using DOS Debug on the A disk or the drive disc, and right after modification, create 0 cylinder 0 head 1 fan Location, restarting the machine is no issue. In case you adjust the partition table parameters to other parameters at random, you are able to use the system disk with DOS installed to begin if you can not get started it. Pressing the 'F3' essential will exit the memory allocation error, you could not load the prompt of your DOS command interpreter COMMAND, The program crashed. Nonetheless, a floppy disk or boot CD formatted as a program disk could be started effectively. As long as there's Debug, you are able to nonetheless modify the partition table parameters back. If unfortunately, the partition table parameters are changed to a circular chain, which is, the subsequent partition of your C drive points towards the D drive, and the subsequent partition from the D drive points to the C drive. This cycle continues, because the logical drive is read endlessly at startup, so Will crash. At this time, as long as there is a hard disk, the laptop or computer cannot be began regardless of the floppy disk or the tough disk. The failure to begin is due to the challenging disk. Even when the difficult disk is installed on a different computer, it can't be used, to ensure that the really hard disk is fully locked. A full hard disk lock plan, but it should be to rewrite the boot program of 0 cylinder 0 head 1 sector, and destroy the partition table or intentionally develop a circular partition table, and put the actual tough disk partition table parameters and boot system in other Hide sectors and shield them. If the password is not appropriate at startup, the laptop can't be began, and in the event the password is appropriate, the laptop starts effectively. This sort of difficult disk lock plan is often started using a boot disk inside a excellent scenario. The critical circumstance is that the boot disk cannot be began. At this time, the difficult disk is locked.

three.five.two Quite a few widespread unlocking techniques 1. 'Hot plug' difficult disk power provide. 'Hot plug' hard drive power will be to not energy on the locked challenging drive when the method is started, and after that 'hot plug' the power cord right after the boot is completed, in order that the method can control the tough drive usually. two. U1traEdit initial prepares a startup disk, after which utilizes a binary editing tool (U1traEdit is advisable) on other typical computer systems to modify the 10.SYS file around the floppy disk (just before the modification, change the file's attributes to regular). Especially, search for the initial '55AA' string within this file and modify it to any other value just after acquiring it. With this modified method floppy disk, you can successfully boot together with the locked really hard disk, but at this time, due to the fact the regular partition table of the really hard disk has been destroyed, after you cannot use Fdisk to delete and modify the partition, it is possible to make use of the partition table Recovery approach to cope with. 3. DMDM ​​is a disk management tool that could perform high-level formatting, low-level formatting, data zeroing, repartitioning, backing up partition tables, and testing disks. It truly is a really helpful tool. It supports all current difficult disk new technologies and has particularly potent functions: rapid, effortless and sophisticated solutions, novice users can effortlessly master the difficult disk installation function, and can totally meet the specific desires of advanced users; completely support the FAT32 supported by the user operating method File program. Format a drive larger than 2GB on a partition. When users make use of the advanced installation mode or menu mode, they can opt for the size of the disk cluster they need to have; break the 8.4GB and 32GB limits; use the really hard disk diagnostic function within the really hard disk subsystem Recognize interrelated challenges; compatible with multiple operating systems, like Windows9X/ME/NT4/2000/DOS/OS/2; help IDE energy management; incorporates multi-sector read and create support for IDE/ATA drives to accelerate data Transfer; Immediately format IDE/ATA/SCSI drives. In most circumstances, the totally installed drive will not exceed 1min; supports high-speed information transfer of enhanced IDE/FASTATA; the low-level formatter incorporated in it is far more sophisticated than the low-level formatter incorporated with numerous BI-OS. It can modify the interleaving factor in the challenging disk, and in some cases repair some difficult disks which have challenges with track 0. Simply because DM is often a difficult disk tool that does not depend on the motherboard BIOS to recognize the hard disk, even though the really hard disk is set to 'NONE' in the motherboard BIOS, the DM can recognize the really hard disk and perform partitioning and formatting operations, so you could also use the DM application to unlock the difficult disk .Initial copy the DM to a technique disk, connect the locked really hard disk and boot up, press the 'Delete' essential to enter the BIOS settings, set all IDE interfaces to 'NONE' and save and exit, then use the floppy disk to begin the system, the system You'll be able to start out with 'lock', mainly because the program is equal to no tough disk at this time. Soon after beginning, run DM. When the DM can recognize the challenging disk, choose the difficult disk to format the partition. This method is easy and convenient, but there's one The fatal shortcoming is that the information around the hard disk can not be kept. When applying DM, the use mode indicates: /m:Manualmode. (manual mode switch)/c.Colormode (color show mode)/p: PC-XT mode/a : PC-AT mode/2: DOS2.XXmode (make DM work in DOS2.XX mode)/3: DOS3.XXmode (make DM operate in DOS3.XX mode)/4: DOS4, XXmode (make DM operate in DOS4.XX Mode)/z: Zen let hMS-DOScompadbil let ymode (the maximum compatibility mode of MS-DOS when DM functions)/w: WyseMS-DOScompadbil off mode (make DM compatible with WyseMS-DOS)/I permit DM to use NECDOS3 The working mode in the substantial partition underNECDOS3.3Only/v: VariableClusterandrootdirectorySizes (alter the size from the cluster plus the quantity of root directories with DM) /0: OperatediSklllallageranddeViCedriveruSlngversiOn2.02conventions (make the DM operate with all the device driver of version two, 02)/i: Selectinterleaveinstallationautomac Pick really hard disk crossover issue)/n: Notwithdefaultparameters (do not use default parameters)/s: Sectorpertrackparametermatching (choose the amount of tracks within the sector)/5: UseWD1005styletranslationscheme (make DM work with WD1005 transmission scheme)/7: USeWD1007StyletransladonSCheme (make DM use WD1007 transmission Project work)/k; specifycytinderSkewandheadSkewforusedUringlow levelinitialization (Forcing cylinder and head offset with DM) /d: Enterbytes-fromindex (BFI) whenAddingnawstothedefectlist (BFI is applied when DM enters defect table. Way) 4. The approach of unlocking the tough disk lock The root cause of really hard disk lock may be the IO.SYS file in DOS. It includes four modules: LOADER, 101, 102, and 103. Among them, 101 contains a crucial system, Syslnt-I. It have to 1st study the partition table for the duration of startup. When the partition table is encountered in a loop, it'll only crash, which can be a really serious defect of DOS. Recognizing that the result in lies in DOS, you can manage the partition table to not be read during the startup process, even the hard disk is just not study, and you can start off effectively. In fact, the technique of realizing the system of unlocking the hard disk is usually to rewrite a set of applications and save it inside the startup disk to start. Throughout the computer's startup course of action, should you pick out to start from the challenging disk, the computer system and disk will initially study the contents of challenging disk 0 cylinder 0 head 1 sector into memory 0000:7C00, and jump to 0000:7C00 to execute. For those who opt for to boot from a floppy disk, the laptop or computer along with the disk will initially study the contents of A disk 0 flux 0 head 1 sector into the memory at 0000:7C00, and jump to 0000:7C00 to execute. Throughout the execution course of action, the computer doesn't Check what the content material in the sector is, and only execute the study command mechanically, to ensure that several systems can survive the virus. But employing this, the plan unlocking approach is just correct. When you format a method floppy disk that may start off the machine with DOS, move the contents of track 0, head 0, and sector 1 on the soft surface to the blank fan in the back. Inside the location, and re-write a system towards the 0 track, 0 head, and 1 sector from the floppy disk, in order that when the floppy disk is started, the plan written prior to is executed first. Within this program, it has some functions: preemptively intercept INT13H ahead of DOS begins, reside in high-end memory and monitor INT13H, ascertain whether or not to read the really hard disk, if it really is to read the tough disk, return directly for the similar, so that the reading in the really hard disk is prohibited. It avoids the crash brought on by DOS reading the really hard disk circular partition table; at the identical time, it intercepts the reading of the floppy disk. If reading the 0 track, 0 head and 1 sector of your floppy disk, it will likely be changed to read the sector with the true boot system and disk parameter table, avoiding DOS Could not locate the disk parameter table from the floppy disk in the course of startup. While finishing these tasks, it really is necessary to study the actual boot plan of your floppy disk and give it control. recover deleted partition table may be known as a versatile, for the reason that it does not handle the difficult disk throughout booting with a floppy disk, so it doesn't matter what approach the really hard disk makes use of to lock, it has no impact on DOS startup. Certainly, the personal computer began in this way does not recognize the hard disk, but this doesn't matter. Right after the computer system begins, you could use Debug to call up the new INT13H program that resides in high-end memory, and adjust it to only one statement that straight executes the old INT13H, in order that you'll be able to use INT12H to study challenging disk 0 cylinder 0 head 1 sector beneath Debug If there is certainly a backup, after the partition table parameters are restored, write 0 cylinder 0 head 1 sector, and restart the laptop. If there isn't any backup, remove the circular chain within the partition table and restart the computer system with all the standard DOS boot disk to at the least re-partition the difficult disk so that the challenging disk is locked and can't be opened. five. Procedures and description ① The following will be the supply program essential.com stored within the floppy disk or optical disk 0 track 0 head 1 sector, the system is input by Debug. 0> debug-a100100CH101XORAX, AX103MOVDS, AX105MOVES, AX107MOVSS, AX109MOVAX, 7000100MOVSP, AX10ESTI10FMOV, SI, AX111MOVDI, 7E00114CLD115MOVCX, 0200118REPNZ119MOVSB11AJMP0000; 7ElF11FMOVCX, 0003122PISHCX123MOVAX, 0201; floppy disk boot sector study enable 126MOVBX, 7000129MOVCX, 4F0112CMOVDX, 010012FINT13131POPCX132DECCX133JNX0122135MOVAX, [0040] Be the first to have the place of INT13H 138MOV[7E88], AX13BMOVAX, [004E]13EMOV[7E8A], AX141MOVAX, [0413]144DECAX145MOV[0413], AX148MOVCL, 0614ASHLAX, CL14CMOVES, AX14EXORAX, AX150MOVDS, copy AX152MOVSI, 7E6, 7E6 Memory 155MOVDI, 0000158MOVCX, 003015BREPNZ015CMOVSB015DMOVAX, 0000; create new INT13H place to interrupt vector table 0160MOV[004C], AX0163MOVAX, ES0165MOV[004E], AX0168JMP0000: 7C00016DPUSHF: new INT13H plan 016ECMPDX, 0080; whether or not it is challenging disk 0172 0174POPF0175IRET; if it can be a tough disk, it returns straight to 0176CMPDX, +00. Do you study the floppy disk BOOT location? 0179JNZ0186017BCMPCX, +01017EJNZ01860180MOVCX, 4F01; yes, read 79 tracks, 1 head, 1 sector, 0183MOVDX, 01000186POPF0187JMP0000:0000; right here, jump to execute the old INT13, the position from the INT13H on the f day is written in the Nkey, comRCX200WQ program soon after the earlier plan is loaded. Prior to proceeding towards the following function, first create a boot disk, test the contents from the boot disk into the CD, and after that use Debug. key.com transfers the program essential.com for the memory offset address of 100H, and writes the segment loading plan at 400H, that is, C>debugkey.com-a400400MOVCX, 0003403PUSHCX404MOVAX, 0201; study the A disk boot plan in to the 1000H 407MOVBX, 1000; so as to make sure success, the initial use of repeated reading 40AMOVCX, 000140DMOV.DX, 0000410INT13412POPCX

413DECCX

414JNZ0403

416MOVAX, 0301; write the floppy disk boot plan that has been study in to the floppy disk

419MOVBX, 1000; the first sector in the last track

41CMOVCX, 4F01

41FMOVDX, 0100

422INT13

424MOVAX, 0301; write key.com plan to floppy disk 0 track 0 head 1 sector

427MOVBX, 0100

42AMOVCX, 0001

42DMOVDX, 0000

430INT13

432INT3

In order to ensure foolproof, the contents of the two sectors with the boot disk needs to be study out again to ensure appropriate writing. Immediately after booting in the floppy disk, the difficult disk will not be recognized, plus the new INT13H plan resides inside the high-end memory. This program is actually part of crucial.com from 16D to 187. Resulting from the existence of this program, the tough disk can't be read beneath Debug, along with the hard disk partition table cannot be restored. As a result, this system must be modified following the laptop or computer is started. This system is located at 9FCO:0000 in memory. Under Debug, use U9FCO:0 to display this system. It may be seen that a jump instruction is positioned at 9FCO.001A, as well as the jump instruction is transferred to execute the original INT13H. Since the BIOS version is different, the place with the jump instruction could possibly be unique. At this time, create a statement beneath Debug: a9FCO:03MPF000:A5D4. In this way, the write prohibition and read prohibition in the really hard disk no longer perform. Below Debug, the partition table on the tough disk is usually read out with the subfunction 2 of INT13H. After gdisk recover partition table is restored, the data is written back to the partition table with the subfunction three. Exit Debug and restart the computer with DOS.

6. Recommend

To greater safeguard the tough disk, it is most effective to back up the difficult disk partition table data. You can find two strategies to back up, a single is to shop the partition info of every single logical disk from the challenging disk within the type of a file; the other is to back up the partition data within the hidden sector with the challenging disk. As an example, you may back up the 0 cylinder 0 head 1 sector in the 0 cylinder 0 head three sector, back up the D disk starting cylinder quantity 0 head 1 sector within the cylinder 0 head three sector, other logical disks in this way. This process is uncomplicated, convenient, and trusted.