After installation here is my ms-dos screen.

I can not figure out what I miss. By the way I formatted all disk sections from c: to d:,e:,f: first and last c: and f: with 1 GB and the rest d: and e: are 2 GB sized. I did it during MS-DOS installing process. My system is DOS 6.22 English.

Despite it installed everything without problems I can not find goriila.bas either.

Thank you in advance.

SYS C:

I did that too.. Again it fails to restart at normal mode without bootdisk.

I did that from "A:\>sys c: " nothing changed even I restarted the system again.

And I also made checkdisk,scandisk all no problem with HDD.

Is this a compact flash card?

If so, it needs MBR boot code.

Run

Fdisk /mbr

No it is classic hard disk with IDE connection. Shall I do "sys c:" from "c:\dos\> " or from "a:\>" ?

boot from floppy
type
fdisk /mbr

try to boot from hard disk

when no success
boot from floppy
type
sys c:

try to boot from hard disk

when no success
boot from floppy
type
chkdsk c:

Sys a: c:

That will copy system files from A to C.

Fdisk /mbr will recreate msdos boot code on sector 0, track 0 of the hard disk.

trivia:

Msdos boots in the following manner:

The bios finishes its POST routine, probes for the fixed disk, then attempts to boot. Traditionally it tries floppy diskettes first.

It does this by reading sector 0, track 0 into memory, then attempting to execute it.

If it fails, it tries the next drive in its list until it either finds executable bootloader code, or until it runs out of drives.

For msdos, 'the boot sector' is a somewhat ambiguous statement. There is the mbr boot sector, at sector 0, track 0, but there is another one located at the first sector of the primary DOS partition.

It's further complicated by the differences between a hard disk and a floppy disk, since floppies are 'partitionless'.

The MBR on hard disks contains the initial boot code, and the partition table. The boot code it contains instructs the computer to parse the partition table, locate the 'active' flag partition, determine which physical sector it starts on, load that sector into memory, then execute it.

If the partition table was made on a nondos system (linux, windows nt flavor os, etc), the MBR wont contain msdos's needed boot block code. The partition may have everything right, but this initial link in the boot chain wont be present.

Fdisk /mbr will read the MBR from the disk, then write it back again with the required boot code.

CF cards come pre-partitioned, and often lack this boot code.

Hard disks initially prepared outside of Dos based systems will also have the table created without this boot code.

On floppy diskettes, since there is no partition, the MBR is 'the same' as the dos boot program that would get loaded at the start of a dos partition. There is no chain loading.

Running sys on a volume will set up the boot code on the partition, but not the initial loader code in the mbr.

Have you considered that you might have a nasty boot sector virus that came from the DOS bootdisk where you installed MS-DOS 6.00 from? try running my portable antivirus program to check for common boot sector viruses..extract and copy it to the boot disk and run it from there after booting from it. Then check both drives A: and C:

good luck!

Usually fdisk /mbr will nuke old bootsector viruses as well.

I'd try that first.

wierd_w wrote on 2025-11-18, 11:47:

Usually fdisk /mbr will nuke old bootsector viruses as well.

I'd try that first.

no it wont if the virus is active it wont allow you to write to the bootsector or MBR..that's the whole point here 😀

(Shrug).

From a cold boot from a known clean diskette it will, but bleh.

wierd_w wrote on 2025-11-18, 11:55:

(Shrug).

From a cold boot from a known clean diskette it will, but bleh.

that error message is from the boot sector of the active partition and not from the MBR.. so your MBR seems to be working fine but the bootsector is unable to locate the system files..but i've seen this message popping up when some buggy boot sector viruses are active butit may not be always the case... so you must do "SYS A: C: " instead of "fdisk/mbr" to fix it. or possibly the partition is not active, so you must use fidsk and set that partition active

Right right...

'INVALID SYSTEM DISK OR DISK ERROR' is part of the mbr code... bleh.

There is a bios specific error, like 'No valid boot device' if it cant find an mbr.

Checking Active is a good call.

this message is from the logical boot sector of the partition created by MS DOS and not from the MBR

I did fdisk/mbr from boot disk, nothing changed...

I have a 5 gb unformatted partition where I see from fdisk. Actually they were formatted when I installed MSDOS 6.22 but they seem to be vanished or not seen anywhere.

I have a question or perhaps a solution middterm. If I install Windoes 95 to remaining part will I have a chance for double Operating System option during start?

Best wishes.

Masaw wrote on 2025-11-18, 11:45:

Have you considered that you might have a nasty boot sector virus that came from the DOS bootdisk where you installed MS-DOS 6.00 from? try running my portable antivirus program to check for common boot sector viruses..extract and copy it to the boot disk and run it from there after booting from it. Then check both drives A: and C:

good luck!

I will try that now.Thank you very much.

I also tried Vckeck, no virus has been found.

so your partition is indeed active looking from those new set of sshots. chances are using "SYS A: C:" should work just fine. however, there is a possibility the hdd has weak/failing sectors located on track zero where the system files should be located and thus the error msg when reading from them