Error in implenting class from .h into .cpp

[Zyrion]

I've been stressing on finding these errors that my compiler is giving me in this code.

ping.h

//=========================
//include guard
#ifndef __PING_H__
#define __PING_H__
//==========================

//==========================
//included dependencies
#include <iostream>
#include <string>
#include <windows.h>
//==========================

class Ping
{
    private:
        string host;
        bool repeater;
    public:
        //============================================================
        // 3x constructors
        Ping()
        {
            host = "127.0.0.1";
            repeater = false;
        }
        Ping(string set = "127.0.0.1")
            :host(set)
        {
            host = set;
            repeater = false;
        }

        Ping(host = "127.0.0.1", bool setRepeat = false)
            :host(set), repeater(setRepeat)
        {
            host = set;
            repeater = setRepeat;
        }
        //=============================================================
        //Methods
        void PingHost()
        {
            do{
                cout << "Host: " + host;
                system (("ping" + host).c_str());
            }while(repeater);

        }
        void setRepeater(bool repeat = false)
            :repeater(repeat)
        {
            repeater = repeat;
        }
        void setHost(string myHost = "127.0.0.1")
            :host(myHost)
        {
            host = myHost;
        }
        //=============================================================
        //destructor
        ~Ping()
        {
            host = "127.0.0.1";
            repeater = false;
        }
};

#endif // PING_H

ping.cpp

#include "ping.h"
#include <string>
#include <iostream>

using namespace std;

int main()
{
    //"216.52.241.254"
    string hostA = "216.52.241.254";
    char reply = 'n';

    Ping *myPing = new Ping(hostA, false);

    cout << "Repeat calls? 'y' or 'n'";
    cin >> reply;

    if(reply == 'n' || reply == 'N')
        myPing->setRepeater(0);
    else if(reply == 'y' || reply == 'Y')
        myPing->setRepeater(1);
    else
        myPing->setRepeater(0);

    myPing->Ping;
    delete myPing; //Changed from ~ping();

    return 0;
}

Error List:

ping.cpp:1: In file included from ..\PingHost\ping.cpp:1:0:

ping.h:17: error: 'string' does not name a type

ping.h:27: error: expected ')' before 'set'

ping.h:34: error: expected ')' before '=' token

ping.h:55: error: 'string' has not been declared

ping.h:55: error: default argument for parameter of type 'int' has type 'const char [10]'

ping.h:-1: In constructor 'Ping::Ping()':

ping.h:24: error: 'host' was not declared in this scope

ping.h:-1: In member function 'void Ping::PingHost()':

ping.h:45: error: 'cout' was not declared in this scope

ping.h:45: suggested alternative:

ping.h:9: In file included from ..\PingHost\ping.h:9:0,

ping.cpp:1: from ..\PingHost\ping.cpp:1:

c:\qt\qt5.0.2\tools\mingw\lib\gcc\i686-w64-mingw32\4.7.2\include\c++\iostream:62: note:   'std::cout'

ping.cpp:1: In file included from ..\PingHost\ping.cpp:1:0:

ping.h:45: error: 'host' was not declared in this scope

ping.h:-1: In member function 'void Ping::setRepeater(bool)':

ping.h:51: error: only constructors take member initializers

ping.h:-1: In member function 'void Ping::setHost(int)':

ping.h:56: error: only constructors take member initializers

ping.h:56: error: class 'Ping' does not have any field named 'host'

ping.h:58: error: 'host' was not declared in this scope

ping.h:-1: In destructor 'Ping::~Ping()':

ping.h:64: error: 'host' was not declared in this scope

ping.cpp:-1: In function 'int main()':

ping.cpp:12: error: no matching function for call to 'Ping::Ping(std::string&, bool)'

ping.cpp:12: candidates are:

ping.cpp:1: In file included from ..\PingHost\ping.cpp:1:0:

ping.h:22: Ping::Ping()

ping.h:22: note:   candidate expects 0 arguments, 2 provided

ping.h:14: Ping::Ping(const Ping&)

ping.h:14: note:   candidate expects 1 argument, 2 provided

ping.cpp:24: error: invalid use of 'Ping::Ping'

ping.cpp:25: error: 'ping' was not declared in this scope