What do you mean by 500 users? 500 concurent users at any given moment in time or 500 during one day?<BR><BR>If the latter, that will work alright with Access. If the former you will probably need another DBMS.<BR><BR>Btw SQL is a language and not a product.
Theoretically, Access 2000 may handle 255 simultaneous connections. Most people would say that performance will start to detoriate significantly when you have more than 20 connections at the same time.