Logon failure: unknown username or bad password.

Hi,
Our web application hosted from  windows 2003 server, is trying to access a file present in a shared folder of another windows 2003 server. The path for the shared folder is configured in the webconfig file in the below format.
<add key="ReportPath" value="\\<Server_Name>\Reports\"/>
In the application, the path is accessed thorough the following piece of code,
 if (!File.Exists(ReportPath)) {    // Show the report in a link} This function File.Exists() always returns false and when I try to remove the check, it returned the exception, "Logon failure: unknown username or bad password."I checked the shared path; have even given full control to 'Everyone' in the shared folder security settings. But still the files are not accessible from the shared folder.I don't prefer ...