Usually comes with modern patches (48-bit LBA, faster file systems, optimized drivers) that make Windows 98 run significantly faster than on its original, slow hardware.
However, booting a standard Windows 98 Second Edition (SE) ISO inside a modern hypervisor like QEMU, KVM, or Proxmox usually results in immediate frustration. You will likely encounter illegal operation errors, missing network drivers, 16-color display limitations, and CPU initialization crashes. windows 98 qcow2 updated