What should I do if the hard disk is maliciously locked?

Q: I downloaded a small program from the Internet. I didn't care at the time and ran it. When I restarted the next day, I found that I couldn't start it. I quickly entered the CMOS test hard disk, and the hard disk could detect it. I started the machine with the WIN98 boot disk, but it could not be started. Start with the A disk, it has not entered the system, it stopped, the hard disk light is always on, there is no reaction at all, this damaged hard disk has important data, what should I do?

A: From the initial estimate you mentioned, it may be a vicious procedure to lock the hard drive, causing the floppy drive to be faked, so that it can't be started. However, it can be handled in the following ways:

Method 1: Modify the Dos startup file. First prepare a DOS6.22 system disk, with tools such as debug, pctools5.0, fdisk. Then on a normal machine, use the familiar binary editing tools (debug, pctools5.0, or ultraedit under Windows) to modify the IO.SYS file on the floppy disk (make sure to change the file's properties to Normal), specifically search for the first "55aa" string in this file, and find it later to change to any other value. With this modified system floppy you can successfully boot with the locked hard drive.

Method 2: Because the so-called "logical lock" is made using a mistake in the IO.SYS file in Microsoft's MS-DOS operating system, and other DOS, such as the PC from IBM -DOS, as well as DR-DOS, FreeDOS, ROM-DOS, etc. do not have this problem. Therefore, when the hard disk is locked by the "logical lock", use the above non-MS-DOS DOS boot disk (can be downloaded in the "DOS system" of the site) to start the system, then execute the FDISK /MBR command. It is very convenient to restore the hard disk to normal.

Method 3: Set the hard disk to None, and then use the DM partition program to re-partition and format it, but the data on the disk will be lost.