QCOW2 files can be used on other platforms with slight adjustments:
A Windows 98 qcow2 image is not a product from Microsoft but a modern container for a classic OS. It works well for light usage, though I/O remains a bottleneck due to the guest’s legacy driver stack. For purists, raw disk images or IDE direct passthrough may be faster, but for flexibility and version control, qcow2 is the superior archival format. windows 98 qcow2
: The following configuration is widely cited for stability: QCOW2 files can be used on other platforms