China DOS Union

Friends:
I downloaded the universal boot disk MS-DOS 7.10. After trying it on my machine, I found that my Win98 could no longer boot. When booting, it shows: Write Protect error writing drive C
Abort,Retry,Fail? Then nothing happens. After booting with a Win98 startup disk, reinstalling the system won't work either. The hard disk is set to read-only, and even formatting doesn't work. I can boot with WinXP and Win2000, though (my machine has three systems installed). What should I do? Thanks!

First use 2000 and take a look.

It seems like your machine's hardware has a problem! It says it's a write error, not a read error!

Generally, in my understanding, a hard disk (partition) is different from a file, and its read-only attribute cannot be set.
But in fact we do see that some hard disks are read-only under special circumstances. How is that done?
Generally speaking, it is done by modifying an interrupt. It changes the interrupt used for writing data to the hard disk (I don't remember exactly which one), and when there is an interrupt request to write data to the hard disk, it redirects to the modified interrupt handler. There, it determines whether you are trying to write data to the hard disk, and which hard disk you are writing to. If it specifies that writing to drive C is not allowed, then there will be a jump to the error message telling you that drive C is write-protected!

But if you boot with a Win98 startup floppy (or CD), then since the interrupt has not been modified at that time, drive C will not be write-protected. In other words, drive C is writable.


“I downloaded the universal boot disk MS-DOS 7.10. After trying it on my machine, I found that my Win98 could no longer boot.”
How exactly did you try it? Please explain in detail, because this is the key. If you don't explain clearly, others can't reproduce your problem. The way we normally test it, this kind of thing does not happen.

In fact, I think maybe it was just a coincidence, but you cannot conclude that it was definitely the “universal boot disk” that caused the trouble.

The following is quoted from minisheep posted on 2003-6-29 8:58:07:
It seems like your machine's hardware has a problem! It says it's a write error, not a read error!

Maybe not.
Because the other drives don't have a “write error”.
Win2000 and XP both work.

I just don't know whether the OP can write to drive C under Win2000.
I think it should be possible.

This is probably not a failure caused by the boot disk. But it's not clear what could make the hard disk become write-protected.

Thank you. On my machine, everything works normally on drive C under Win2000 and WinXP.

The OP can try the following method. This is generally how I solve disk logical protection problems:
1 Use FDISK/MBR to rebuild the partition table
2 Use FDISK or PQ to delete the C partition and then recreate it

Hard disk write protection can be implemented by writing a piece of checking code into a later free sector on track 0, then modifying the jump in the track 0 boot information. After booting, it first calls the checking code in the back to stay resident in memory, and then this program can take over INT13 to determine whether the operation is writing to the hard disk. If it is a write, then it intercepts it; otherwise it normally calls the original INT1
3 so that it can run normally.

In principle it can be implemented like this, but I don't know how to do it in programming terms~~~ because I don't know programming, hehe~~~

I wonder whether the OP ever installed things like Restore Wizard or Kingsoft Protector. If so, they very likely caused this~~~

Try setting the “virus protection” option in BIOS to “disabled”.