You need to use two threads
class MainClass
{
public static void Main()
{
Task.Factory.StartNew(MainClass.test2);
Task.Factory.StartNew(MainClass.Update);
Console.ReadLine();
}
public static void test2()
{
while (true)
{
System.Threading.Thread.Sleep(500);
Console.WriteLine("Test");
}
}
public static void Update()
{
while (true)
{
Console.WriteLine("Hello");
System.Threading.Thread.Sleep(250);
}
}
}