cboys00 wrote:if to set up MySQL server,
after install xampp, can i set up MySQL server or need to install others sw???
On the client PCs you dont need any SQL software. Of course Xampp installs MySQL (i dont know if one can choose at installation time, whether to install certain parts or not), but that does not matter anyway. You dont need to start the clients MySQL (its not needed). Even if you start it, it wont have any effect to your central server.
The only thing you have keep in mind, when running PHP scripts which access MySQL, you MUST NOT use "localhost" for the connect, instead use the LAN IP (or servername) of the MySQL Server. And also apply the username (which you created on the Server) and password instead of "root".
Finally - why do you put Apache on each client PC? You also could put that on the same server as MySQL, you could also create userspaces on the server where you put the userfiles and then you have a clean server/client architecture. There is no need to put a server environment like Xampp on client machines, thats kind of odd.