C# code behaving weird while in a loop
<p>When I try to add a loop to my code, it starts to assume decisions and adds "f" or "d" to the start of some writelines.
The first 8 lines of the application are correct</p>

<p><a href="http://i.stack.imgur.com/eV17U.png" rel="nofollow">Picture of console</a> </p>

<p>The code loops at "Press any key to continue"</p>

<p>Code:</p>

<pre><code>using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RockPaperScissors
{
    class Program
    {
    static void Main(string[] args)
    {
        {
            int userScore = 0;
            int computerScore = 0;
            for (int isRunning = 0; isRunning &lt; 10;)
            {
                Random rnd = new Random();
                int computerChoice = rnd.Next(1, 150);
                Console.WriteLine("Welcome to rock, paper, scissors!");
                System.Threading.Thread.Sleep(400);
                Console.WriteLine("Press escape to exit");
                Console.Write("Rock, paper or scissors? ");
                string userChoice = Console.ReadLine();
                if (userChoice == "rock")
                {
                    if (computerChoice &lt;= 50)
                    {
                        Console.WriteLine("The computer chooses rock.");
                        System.Threading.Thread.Sleep(1000);
                        if (userChoice == "rock")
                        {
                            Console.WriteLine("Tie!");
                            System.Threading.Thread.Sleep(500);
                            Console.WriteLine("Computer score is: " + computerScore + "!");
                            Console.WriteLine("Your score is: " + userScore + "!");
                            System.Threading.Thread.Sleep(500);
                            Console.WriteLine("Press any key to continue");
                            Console.ReadKey();
                        }
                        else if (userChoice == "paper");
                        {
                            Console.WriteLine("Paper beats rock! You win!");
                            userScore++;
                            System.Threading.Thread.Sleep(1000);
                            Console.WriteLine("Computer score is: " + computerScore + "!");
                            Console.WriteLine("Your score is: " + userScore + "!");
                            System.Threading.Thread.Sleep(500);
                            Console.WriteLine("Press any key to continue");
                            Console.ReadKey();
                        } }
                    else if (userChoice == "scissors")
                    {
                        Console.WriteLine("Rock beats scissors. You lose!");
                        computerScore++;
                        System.Threading.Thread.Sleep(1000);
                        Console.WriteLine("Computer score is: " + computerScore + "!");
                        Console.WriteLine("Your score is: " + userScore + "!");
                        System.Threading.Thread.Sleep(500);
                        Console.WriteLine("Press any key to continue");
                        Console.ReadKey();
                    }

                }
                if (computerChoice &gt;= 51 &amp;&amp; computerChoice &lt;= 100)
                {
                    Console.WriteLine("The computer chooses scissors.");
                    System.Threading.Thread.Sleep(1000);
                    if (userChoice == "rock")
                    {
                        Console.WriteLine("Rock beats scissors! You win!");
                        userScore++;
                        System.Threading.Thread.Sleep(500);
                        Console.WriteLine("Computer score is: " + computerScore + "!");
                        Console.WriteLine("Your score is: " + userScore + "!");
                        System.Threading.Thread.Sleep(500);
                        Console.WriteLine("Press any key to continue");
                        Console.ReadKey();
                    }
                    else if (userChoice == "paper")
                    {
                        Console.WriteLine("Scissots cut paper! You lose.");
                        computerScore++;
                        System.Threading.Thread.Sleep(1000);
                        Console.WriteLine("Computer score is: " + computerScore + "!");
                        Console.WriteLine("Your score is: " + userScore + "!");
                        System.Threading.Thread.Sleep(500);
                        Console.WriteLine("Press any key to continue");
                        Console.ReadKey();
                    } }
                else if (userChoice == "scissors")
                {
                    Console.WriteLine("Tie!");
                    System.Threading.Thread.Sleep(1000);
                    Console.WriteLine("Computer score is: " + computerScore + "!");
                    Console.WriteLine("Your score is: " + userScore + "!");
                    System.Threading.Thread.Sleep(500);
                    Console.WriteLine("Press any key to continue");
                    Console.ReadKey();
                }
                if (computerChoice &gt;= 101)
                {
                    Console.WriteLine("The computer chooses paper.");
                    System.Threading.Thread.Sleep(1000);
                    if (userChoice == "rock")
                    {
                        Console.WriteLine("Paper beats rock! You lose.");
                        computerScore++;
                        System.Threading.Thread.Sleep(500);
                        Console.WriteLine("Computer score is: " + computerScore + "!");
                        Console.WriteLine("Your score is: " + userScore + "!");
                        System.Threading.Thread.Sleep(500);
                        Console.WriteLine("Press any key to continue");
                        Console.ReadKey();
                    }
                    else if (userChoice == "paper")
                    {
                        Console.WriteLine("Tie!");
                        System.Threading.Thread.Sleep(1000);
                        Console.WriteLine("Computer score is: " + computerScore + "!");
                        Console.WriteLine("Your score is: " + userScore + "!");
                        System.Threading.Thread.Sleep(500);
                        Console.WriteLine("Press any key to continue");
                        Console.ReadKey();
                    }
                }
                else if (userChoice == "scissors")
                {
                    Console.WriteLine("Scissors cut paper! You win!");
                    userScore++;
                    System.Threading.Thread.Sleep(1000);
                    Console.WriteLine("Computer score is: " + computerScore + "!");
                    Console.WriteLine("Your score is: " + userScore + "!");
                    System.Threading.Thread.Sleep(500);
                    Console.WriteLine("Press any key to continue");
                    Console.ReadKey();
                }
            }
            if (computerScore &gt; userScore)
            {
                Console.WriteLine("Game over!");
                Console.WriteLine("The computer won this round. Better luck next time.");
                Console.WriteLine("Press any key to continue.");
                Console.ReadKey();
            }
            else if (userScore &lt; computerScore)
            {
                Console.WriteLine("You win!");
                Console.WriteLine("You beat the computer! Good job.");
                Console.WriteLine("Press any key to continue.");
                Console.ReadKey();
            }
        }
    }
}
}
</code></pre>

<p>Thanks and sorry for the long code</p>