connection failed - ODBC from remote SQL SERVER

hello,
im trying to create an ODBC data source from a SQL SERVER 2005 database located in a remoted pc.
Client---->PC1 : win 2000 sp4, not sql server
Remote server-->PC2 : win 2000 sp4, sql server 2005 express

From the Command Prompt, im typing "ping PC2" successfully.
After, in the ODBC datasource administrator-->System DNS tab, i choose "sql server" as a new data source , and in the server box , i'm typing PC2/SQLEXPRESS.

In the next steps, im typing the user-passwords.
The error :
connection failed
...
[microsoft][odbc sql server driver][named pipes]ConnectionOpen(CreateFile()).
Connection failed:
SQLState: '08001'
..
Client unable to establish connection

What goes wrong?
I follow the same steps locally, and everything is OK.

Sorry for my bad english:cool:Here's an article (http://blogs.msdn.com/sql_protocols/archive/2006/03/23/558651.aspx) on troubleshooting connectivity issues on SQL Server Express.|||SQL 2005 does not support the Named Pipes protocol by default. I would choose a different protocol, preferably TCP/IP. You can set the protocol using the Client Configuration button on the second screen of the DSN definition in the ODBC DSN applet.

-PatP