با استفاده از کد زیر میتونین خطا ها رو در WinForms مدیریت کنین

static class Program
{
    [STAThread]
    static void Main()
    {
        // Add handler to handle the exception raised by main threads
        Application.ThreadException += 
        new System.Threading.ThreadExceptionEventHandler(Application_ThreadException);

        // Add handler to handle the exception raised by additional threads
        AppDomain.CurrentDomain.UnhandledException += 
        new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException);

        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());

        // Stop the application and all the threads in suspended state.
        Environment.Exit(-1);            
    }

    static void Application_ThreadException
        (object sender, System.Threading.ThreadExceptionEventArgs e)
    {// All exceptions thrown by the main thread are handled over this method

        ShowExceptionDetails(e.Exception);
    }

    static void CurrentDomain_UnhandledException
        (object sender, UnhandledExceptionEventArgs e)
    {// All exceptions thrown by additional threads are handled in this method

        ShowExceptionDetails(e.ExceptionObject as Exception);

        // Suspend the current thread for now to stop the exception from throwing.
        Thread.CurrentThread.Suspend();
    }

    static void ShowExceptionDetails(Exception Ex)
    {
        // Do logging of exception details
        MessageBox.Show(Ex.Message, Ex.TargetSite.ToString(), 
                MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}  

برای اطلاعات بیشتر میتونین از لینک زیر استفاده کنین 

Centralised-Exception-Handling-in-C-Windows-Applic