Hello @Paul Zimamoto Thank you for reaching out to us on Microsoft Q&A platform. Happy to help!
From the description I understand that you are looking to enable replication for your Window Server 2003 machine. However, it is failing to install mobility service on Window Server 2003 machine.
To answer your question:
Does Azure Site Recovery Mobility Service support Windows Server 2003?
Short answer: No!
Azure Site Recovery Mobility Service does not support Windows Server 2003. The Mobility Service is a lightweight agent that needs to be installed on the source machine to enable replication to Azure. However, it only supports Windows Server 2008 R2 and later versions of Windows Server. This means that if you have Windows Server 2003 machines that you want to replicate to Azure, you will need to upgrade them to a supported version of Windows Server before you can use Azure Site Recovery to migrate them to Azure.
It's worth noting that Windows Server 2003 reached end of support on July 14, 2015, which means that it no longer receives security updates. Therefore, it's recommended that you upgrade to a supported version of Windows Server as soon as possible to ensure that your environment is secure and up to date.
Hope this answer your question. Please write back to us if you have any further questions.
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