What are the best options for moving 25 legacy Windows VMs off VMware?

The right answer depends heavily on what is hiding behind “Windows 2003, XP, etc.” If there are even older systems such as OS/2 or CP/M, the migration requirements could be very different. Identify the OS, application, dependencies, network requirements, and hardware assumptions for every VM before selecting a target platform.

One proof of concept involved converting a Windows Server 2003 VMware machine to Hyper-V locally, installing the necessary integration tools, and uploading the resulting VHD to an Azure storage account. It worked, but it was not a supported production design. You could also preserve the old systems inside a newer host using nested virtualization, but Microsoft will not support troubleshooting failures on those legacy guests, so isolation, backups, and a well-tested rollback plan would be essential.

Azure VMware Solution would probably be the least disruptive because the existing VMs could remain largely unchanged, but it is likely expensive and excessive for only 25 machines. Nutanix NC2 on Azure is another possibility and may provide migration tooling. Moving directly to Azure VMs is also an option, although the unsupported operating systems would create compatibility and support problems. Before choosing, inventory what each VM actually does—some workloads may be candidates for modernization or replacement rather than a straight lift-and-shift.

If the applications cannot be upgraded immediately, treat this as a preservation project rather than a normal cloud migration. Keep the legacy VMs isolated, restrict their network access, capture full image-level backups, and test restores on the proposed platform. In parallel, plan to replace or modernize the applications so the unsupported operating systems are not a permanent dependency.