can you please be more specific with the question "now can any one tell if the uses continue to use winxp or window 2003 member to login , files share etc?" I think I am missing something here.
In General you can enable SMBv1 (although not recommended) and ensure the backwards compatibility, but you need to consider one more thing - enabling the support for older encryption algorithms like RC4. You can refer to the following MS Docs article for more detail on the Kerberos encryption protocol compatibility:
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