Quick & dirty script C# script to fetch WLAN passwords without Admin rights.

gistfile1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Diagnostics;

namespace WlanPasswords
{
    class Program
    {
        static List<string> GetProfiles()
        {
            var list = new List<string>();
            using (var p = new Process())
            {
                p.StartInfo.FileName = "netsh.exe";
                p.StartInfo.Arguments = "wlan show profiles";
                p.StartInfo.UseShellExecute = false;
                p.StartInfo.RedirectStandardOutput = true;
                p.Start();

                string output;
                bool dumping = false;
                while ((output = p.StandardOutput.ReadLine()) != null)
                {
                    if (!dumping)
                    {
                        if (output.StartsWith("User profiles"))
                        {
                            p.StandardOutput.ReadLine();
                            dumping = true;
                        }
                    }
                    else
                    {
                        var splitted = output.Trim().Split(' ');
                        if (splitted.Length > 3)
                        {
                            list.Add(string.Join(" ", splitted, 8, splitted.Length - 8));
                        }
                    }
                }
            }
            return list;
        }

        static string GetPassword(string profile)
        {
            using (var p = new Process())
            {
                p.StartInfo.FileName = "netsh.exe";
                p.StartInfo.Arguments = string.Format("wlan show profiles name=\"{0}\" key=clear", profile);
                p.StartInfo.UseShellExecute = false;
                p.StartInfo.RedirectStandardOutput = true;
                p.Start();

                string output = p.StandardOutput.ReadToEnd();
                if (output.Contains("not found on the"))
                    return "NONE";

                var keyOffset = output.IndexOf("Key Content") + "Key Content".Length;
                if (keyOffset < 0)
                    return "NONE";
                keyOffset = output.IndexOf(':', keyOffset) + 2;
                var keyStop = output.IndexOf('\n', keyOffset) - 1;
                return output.Substring(keyOffset, keyStop - keyOffset);
            }
        }

        static void Main(string[] args)
        {
            Console.Title = "WLAN Dumper";
            Console.WriteLine("WLAN Password Dumper (c) 2013 Cedric Van Goethem");
            Console.WriteLine("---------------------");
            foreach (var profile in GetProfiles())
            {
                Console.WriteLine("{0}:\t{1}", profile, GetPassword(profile));
            }
            Console.WriteLine("---------------------");
            Console.WriteLine("Press any key to continue...");
            Console.ReadKey();
        }
    }
}