Prime Number Finder

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    int counter = 0;
    int j = 3;
    int input;
    bool registered;

    ofstream primeOutput;
    primeOutput.open("output.txt");

    cout << "Enter A Number and I will find all the prime number from 1 - X: ";
    cin >> input;
    if (input >= 2)
    {
        primeOutput << 2 << "\n";
        counter++;
    }


    for (int i = 1; i <= (input); i = i + 2)
    {
        registered = false;
        for (int j = 1; j < 10; j++)
        {
            if ((i % j == 0) && (i != j) && (j != 1) && !registered || (i == 1))
            {
                registered = true;
            }
            else if (!registered && (j == 9))
            {
                primeOutput << i << "\n";
                counter++;
            }

        }
    }
    cout << "Solutions can be found in this file's directory named \"output.txt\"" << endl;

    system("pause");
    return 0;
}