Post your installation steps. What did you actually do? Did Windows setup finish successfully?

feda wrote on 2023-04-16, 15:19:

Post your installation steps. What did you actually do? Did Windows setup finish successfully?

Yes, of course.

You could open the image with winimage or 7-zip etc. and check if the files are still there(at least IO.SYS).
Then if they're present, check the MBR by running A:FDISK /MBR from a Windows floppy disk (actually MS-DOS 7.1) created or used during installation). You'll need to "cd C:" first though (it's mounted drive letter) to make fdisk check it properly.
Otherwise (unlikely though) you might need to do a repair install from the installation media (or local copy of it, if on the hard disk image itself).

FDISK /MBR is a good idea. Also make sure that the Windows partition is marked "active" (you can do that in the interactive user interface of FDISK).

Checking the BIOS' and changing the hard drive type can also help (i.e. LARGE, LBA, etc)

sys c:

jakethompson1 wrote on 2023-04-17, 03:56:

sys c:

That might depend. I don't know if the MSDOS.SYS that's written is for Windows 9x boot or MS-DOS boot. If not Windows 9x-compatible, it destroys the Windows permanently, requiring a reinstall of Windows to fix.

This is quite interesting. I'm more used to the "No Bootable Device, Insert Boot Disk and Press Any Key" error. But I would assume the error still originates in the BIOS, because this is not an MSDOS error I've ever seen.

So while I agree with the advise provided above, let's just walk through some steps.

CASE 1. BIOS cannot see bootable device.

1. Hardware connection issues (cable/jumper etc.)/in case of emulated hardware, settings for the emulated device. The solution would be to open up the settings and see if something looks off. Maybe plug in a working disk image and compare the settings.
2. BIOS settings. Hard drive is not properly detected and/or set up. The solution would depend on the specific BIOS. Make sure the HDD is set up as a bootable device. Sometimes bootable disks don't work properly when set up on SCSI or as a secondary device.
3. You may have left a non/bootable floppy disk inside, even if it's emulated. Back in the day, if the computer found a non-bootable floppy disk in the drive, it wouldn't automatically try to boot from the HDD.

CASE 2. The problem is on the HDD.

1. MBR is damaged or missing. As mentioned by mkarcher, booting from a Windows 95 recovery disk or an MSDOS disk and typing in fdisk /mbr will rewrite your MBR without altering the partition table.
2. In Win9x and MSDOS, MBR looks for files called IO.SYS and MSDOS.SYS. You can copy those files from your Windows 95 recovery disk (NOT THE MSDOS DISK) to your hard drive and overwrite them, if necessary. The minimum viable bootable disk from that era should contain IO.SYS, MSDOS.SYS and COMMAND.COM in its root directory, if memory serves me. I do not recommend touching CONFIG.SYS and AUTOEXEC.BAT at this time. Once the operating system is discovered, even if it doesn't boot properly, you can repair your installation.

Hope you get it fixed soon.

songoffall wrote on 2023-04-17, 20:49:

This is quite interesting. I'm more used to the "No Bootable Device, Insert Boot Disk and Press Any Key" error. But I would assume the error still originates in the BIOS, because this is not an MSDOS error I've ever seen.

As I remember it, "Missing operating system" is the error message from an MBR that fails to load the boot loader for the active partition.

songoffall wrote on 2023-04-17, 20:49:

MBR is damaged or missing. As mentioned by mkarcher, booting from a Windows 95 recovery disk or an MSDOS disk and typing in fdisk /mbr will rewrite your MBR without altering the partition table.

Credit where credit is due: superfury suggested fdisk /mbr first. My primary suggestion was to make sure that the correct partition is active.

mkarcher wrote on 2023-04-17, 21:11:

songoffall wrote on 2023-04-17, 20:49:

MBR is damaged or missing. As mentioned by mkarcher, booting from a Windows 95 recovery disk or an MSDOS disk and typing in fdisk /mbr will rewrite your MBR without altering the partition table.

Credit where credit is due: superfury suggested fdisk /mbr first. My primary suggestion was to make sure that the correct partition is active.

I stand corrected.

One more thing: fdisk /mbr will rebuild the MBR on the current disk, which might not be the one used for the Windows installation (like the floppy disk). I think fdisk /cmbr c: would be a more foolproof use of the command.

songoffall wrote on 2023-04-17, 21:54:

mkarcher wrote on 2023-04-17, 21:11:

songoffall wrote on 2023-04-17, 20:49:

MBR is damaged or missing. As mentioned by mkarcher, booting from a Windows 95 recovery disk or an MSDOS disk and typing in fdisk /mbr will rewrite your MBR without altering the partition table.

Credit where credit is due: superfury suggested fdisk /mbr first. My primary suggestion was to make sure that the correct partition is active.

I stand corrected.

One more thing: fdisk /mbr will rebuild the MBR on the current disk, which might not be the one used for the Windows installation (like the floppy disk). I think fdisk /cmbr c: would be a more foolproof use of the command.

The MBR used shouldn't be an issue, provided the disk booted is created during the install wizard (or compatible with the filesystem mainly).

https://en.m.wikipedia.org/wiki/IO.SYS

Assuming Windows 9x is on the disk, the boot process in the MBR is identical to MS-DOS (first 4 sectors of IO.SYS loaded (not required for MS-DOS 7.1 and Win9x type boot sector at least), followed by IO.SYS loading other sector done by code located in the first IO.SYS 3 sectors instead of MBR code (located at it's entry point)).

The only difference between MS-DOS and Windows IO.SYS is that Windows IO.SYS is basically MSDOS.SYS+IO.SYS (and MSDOS.SYS is reduced to a config.sys formatted text file, which specifies to load Windows 9x's win.com using specific triggers not in MS-DOS 6.22 and below).
On MS-DOS 6.22 and below IO.SYS chainloads MS-DOS.SYS as an driver(don't know if just driver-ish (special loaded) or a driver like any other (like himem.sys and any other driver)), followed by MSDOS.SYS loading COMMAND.COM.
Said process using IO/MSDOS.SYS is the same for booting Windows in MS-DOS mode as well (Just real MS-DOS.SYS being merged into or embedded within IO.SYS).
You could open up MSDOS.SYS in a text file editor and see the config.sys-like commands in it.

superfury wrote on 2023-04-18, 21:02:

The MBR used shouldn't be an issue, provided the disk booted is created during the install wizard (or compatible with the filesy […]
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songoffall wrote on 2023-04-17, 21:54:

mkarcher wrote on 2023-04-17, 21:11:

Credit where credit is due: superfury suggested fdisk /mbr first. My primary suggestion was to make sure that the correct partition is active.

I stand corrected.

One more thing: fdisk /mbr will rebuild the MBR on the current disk, which might not be the one used for the Windows installation (like the floppy disk). I think fdisk /cmbr c: would be a more foolproof use of the command.

The MBR used shouldn't be an issue, provided the disk booted is created during the install wizard (or compatible with the filesystem mainly).

https://en.m.wikipedia.org/wiki/IO.SYS

Assuming Windows 9x is on the disk, the boot process in the MBR is identical to MS-DOS (first 4 sectors of IO.SYS loaded (not required for MS-DOS 7.1 and Win9x type boot sector at least), followed by IO.SYS loading other sector done by code located in the first IO.SYS 3 sectors instead of MBR code (located at it's entry point)).

The only difference between MS-DOS and Windows IO.SYS is that Windows IO.SYS is basically MSDOS.SYS+IO.SYS (and MSDOS.SYS is reduced to a config.sys formatted text file, which specifies to load Windows 9x's win.com using specific triggers not in MS-DOS 6.22 and below).
On MS-DOS 6.22 and below IO.SYS chainloads MS-DOS.SYS as an driver(don't know if just driver-ish (special loaded) or a driver like any other (like himem.sys and any other driver)), followed by MSDOS.SYS loading COMMAND.COM.
Said process using IO/MSDOS.SYS is the same for booting Windows in MS-DOS mode as well (Just real MS-DOS.SYS being merged into or embedded within IO.SYS).
You could open up MSDOS.SYS in a text file editor and see the config.sys-like commands in it.

And that's the reason why you shouldn't copy IO.SYS and MSDOS.SYS from the MSDOS disk to a Windows 9x machine 😀)

What I was saying was; if you boot from a floppy drive A: and do an fdisk /mbr command, it will rebuild the MBR on the floppy disk. fdisk /cmbr c: is a reliable way of rebuilding the MBR on the C: disk.

ATM I just don't know where the error "missing operating system" originates.

Microsoft says it originates in the BIOS, and suggests the following reasons:

• The basic input/output system (BIOS) does not detect the hard disk.
• The hard disk is damaged.
• Sector 0 of the physical hard disk drive has an incorrect or malformed master boot record (MBR).
• An incompatible partition is marked as Active.
• A partition that contains the MBR is no longer active.

https://support.microsoft.com/en-us/topic/-op … 93-d8fbe5fd4608

But, looking at the MBR, it does contain the "missing operating system" error string:

https://www.researchgate.net/figure/Snapshot- … _fig1_316054480

superfury wrote on 2023-04-17, 06:18:

jakethompson1 wrote on 2023-04-17, 03:56:

sys c:

That might depend. I don't know if the MSDOS.SYS that's written is for Windows 9x boot or MS-DOS boot. If not Windows 9x-compatible, it destroys the Windows permanently, requiring a reinstall of Windows to fix.

You can simply show hidden files in Win10/11 and copy everything in root to a folder then run sys c: and replace the files sys c: overwrote. that's what I do and it works flawlessly. I can even use this method for cloning installs of win9x/3x/dos