Hello,

 Our problem:

 Trying to connect database on 1c server by thin client. The server is appears on the local
 network. (We can connect to server as 'remote desktop' already.) There is time out message...  

 (Server Op.System: Windows Server 2003 )

 We added the local ip and machine name in . ./etc/host. : there was no change.

 But before formatted the machine, connection was realised normally.

Hello, Veli Bıçakçı!

Please check first if ports that are used for connection are opened in server firewall.
Also please tell, if you are using Thin client over http protocol or by direct connection to the server? As for http mode thin client should be published on the web server and for direct connection 1541 (or configured manually port) should be accessible for client PC.