logon failure........ when accessing remote file

ihve 2 systems 1) webserver(username=ws passowrd=abc )  2) dbserver (username=ds passowrd=xyz )

in webserver web config i have given identity imperosonate =true username="webserver\ws" password="abc"

i have a code for downloading the file from  dbserver to webserver


                Response.AddHeader("Accept-Ranges", "bytes")
                Response.AppendHeader("ETag", """" & _EncodedData & """")
                Response.AppendHeader("Last-Modified", lastUpdateTiemStamp)
                Response.ContentType = "application/octet-stream"
            &nbs ...