can Win2k Pro support more than 10 user?

There not all on line at once instead of using 2000 Pro you should be using 2000 Server this does not have this limit but it does cost more. It is cases like this that saving the few dollars in the first place gives you a long time to regret the bargin that you obtained instead of buying what you need. Of course if you where sold this product under the understanding that it could support more than 10 users concurently then you have a comeback against whoever sold you the product but if you chose it simply because of cost then it's your fault and you have to live with the problems or fork out the money for a copy of 2000 Server but as 2003 is coming out very soon I'd probably wait for that as it will be available within a month.

The actual limitation is not number of users, but number of concurrent connections.

You may have 20 users, but if only 5 of them are connected at any one moment, you won't bump against the limitation.

Conversely, a single user connected from 10 different computers will cause the limitation to be reached.