Re: Windows NT 4.0

[Jakob Bohm]

On 2023-02-08 14:55, Wilson Birney wrote:

I have a windows NT 4.0 raw image that when converted with qemu-img to qcow2 or vmdk fails to boot in qemu with no obvious error using the following:

qemu-system-i386 -m 128 -cpu pentium -hda f.qcow2

It just hangs at 'Booting from Hard Disk...." and pegs out a cpu core.

This same image boots just fine in vmware Workstation and virtualbox when i convert to a vmdk.

Any ideas on what could be causing this or what to do to diagnose it?

Check the virtual hard disk interface.  The NT 4.0 boot process relies on some files
in the root directory providing details of that hardware, for example the driver for
virtio-scsi or vmware-scsi.  Or an indication to use standard IDE/SATA drivers.  This
also includes which partition contains Windows.  Some of this is in the text file
BOOT.INI, other parts are in code files in the root, such as a .SYS file for the SCSI
driver.

As a result, any virtual disk for running NT 4.0 under virtualization will be specific to
the disk, display and CPU hardware of that VM configuration.

Fortunately however, there are qemu utilities to mount the virtual disk under the host
OS, where an appropriate file system driver can access the FAT, NTFS or HPFS contents
for r/w and thus potentially change of this hardware information.  To access registry
settings it is more practical to mount the disk as a secondary disk in a VM that boots
from a minimalist Windows system such as WinPE, from which the secondary disk
registry files can be mounted elsewhere in the registry tree for editing.

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Jakob Bohm, CIO, partner, WiseMo A/S. https://www.wisemo.com
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