Broken Windows Service after IP change

Hi, I had a Windows service created which updates a SQL stored procedure but when I changed the IP on my SQL server it stopped working and now it creates an ODBC error 2012-12-11 00:01:15,586 [5656] ERROR [login to view URL] [(null)] - Error detail: ERROR [08001] [Microsoft][ODBC SQL Server Driver][DBNETLIB]SQL Server does not exist or access denied. Any idea what we need to do to fix it because I cannot see an ODBC connection which isn't working? Thanks Owain