Hello @Mahavir Saroj Thank you for posting your question on Microsoft Q&A platform. Happy to help!
From title it looks like you want to migrate your on-premises Windows Server 2003 32 bit to Azure. However, in the details you have mentioned about wanting to use backup solution in Azure.
If I understand it correctly, you want to migrate the on-premises server to Azure and enable backup as well. You can use Azure Migrate which is capable of migrating/replicating Windows Server 2003 running on Hyper-V/VMware (both 32/64 bit) provided Hyper-V integration Services has been installed (for the VM to be able to boot after it is migrated to Azure). There is no support for physical but P2V VHD upload might work.
Reference doc - https://learn.microsoft.com/en-us/azure/migrate/prepare-windows-server-2003-migration
FAQ link - https://learn.microsoft.com/en-US/troubleshoot/azure/virtual-machines/run-win-server-2003
Regarding backup solution, Azure backup doesn't support backup of Windows Server 2003. Because the Azure VM agent and extensions do not support Windows Server 2003. You may want to check if there is any 3rd party solution that supports this scenario.
Hope this helps. Please write back to us if you have any questions!
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