关于数据备份问题

我想把数据备份，但是总是出现一下错误，不知道是什么原因。请高手指教、代码如下：
private void Linkbutton3_Click(object sender, System.EventArgs e)
        {
            //数据库备份
            string syspath = Server.MapPath("~/data/");
            SQLBACK("127.0.0.1", "sa", "", "peisong", syspath  );

        }

        protected void SQLBACK(string ServerIP, string LoginUserName, string LoginPass, string DBName, string BackPath)
        {
        
            SQLDMO.Backup oBackup = new SQLDMO.BackupClass();
            SQLDMO.SQLServer oSQLServer = new SQLDMO.SQLServerClass();
            try
            {
                oSQLServer.LoginSecure = false;
                oSQLServer.Connect(ServerIP, LoginUserName, LoginPass);
                oBackup.Action = 0;
                oBackup.Database = DBName;
                oBackup.Files = @" " + BackPath + "peisong.bak";
                oBackup.BackupSetName = DBName;
                oBackup.BackupSetDescription = "数据库备份";
                oBackup.Initialize = true;
                oBackup.SQLBackup(oSQLServer);
                Response.Write("<script>alert('数据备份成功！')</script>");
            }
            catch (Exception e)
            {
                throw new Exception(e.ToString());
            }
            finally
            {
                oSQLServer.DisConnect();
            }
        }

“/zyp”应用程序中的服务器错误。
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System.Runtime. (0x80040000): [Microsoft][ODBC SQL Server Driver][DBNETLIB]SQL Server 不存在或访问被拒绝 [Microsoft][ODBC SQL Server Driver][DBNETLIB]ConnectionOpen (Connect()). at SQLDMO.SQLServerClass.Connect(Object ServerName, Object Login, Object Password) at zyp.left.SQLBACK(String ServerIP, String LoginUserName, String LoginPass, String DBName, String BackPath) in e:\ps\zyp\left.aspx.cs:line 243