Need Help. Why it can't Print Exact Output (in C#)?

Question

/* Write a C# program to compute the sum of the first 500 prime numbers. Go to the editor
Output:
3682913
*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
namespace ConsoleApplication8
{
class Program
{
static void Main(string[] args)
{
int num, i,l;
int sum = 0;
l = 0;
for (num = 1; ;num++ )
{
int k = 0;
for (i = 1; i <= num; i++)
{
if (num % i == 0)
{
k++;
}
}
if (k == 2)
{
Console.WriteLine("Number is {0}", num);
sum += num;
l++;
if (l == 500)
{
Console.WriteLine("Sum is {0}", sum);
break;
}
}
else
{
}
}
Console.WriteLine("Sum is {0}", sum);
Console.WriteLine("Total Number is {0}", l);
}
}
}

Answer 1

Are you running this on SL or locally on your machine?

Answer 2

This looks to cause an infinite loop
for (num = 1; ;num++ )
This seems to be limiting your sum calculations
if (k == 2)
{