You can install Symantec Antivirus on Windows XP Professional or Windows 2000 Professional, and therefor you can still hace centralized management for SAV...
If you just have Windows XP Home edition... well.. then you could technically write a script that will distribute an XDB-file to all the 7.5 directories on the SAVCE clients, which will then be automatically be processed.
I guess anything is possible with the right permissions and the right scripts... I would however try sticking to a Symantec Antivirus Server -> Symantec Antivirus Client setup without the use of a true Server OS like Windows 2000/2003.