MAC Address is: 0:0:0:0:0:0 and Scanning available networks...

Hi,
I am using the Arduino UNO board and Arduino WIFI shield top on it, Looks to be setup are fine, even though, we are getting failure message,
Initializing Wifi...
MAC: 0:0:0:0:0:0
Scanning available networks...
** Scan Networks **
number of available networks:0
Scanning available networks...
** Scan Networks **
number of available networks:0
Scanning available networks...
** Scan Networks **
number of available networks:0
Scanning available networks...
** Scan Networks **
number of available networks:0
Scanning available networks...
** Scan Networks **
number of available networks:0
Scanning available networks...
** Scan Networks **
number of available networks:0
Scanning available networks...
** Scan Networks **
number of available networks:0
Scanning available networks...
** Scan Networks **
Also, the mac address of the Arduino board show as “MAC: 0:0:0:0:0:”

Here, you can find the code snippet here,

#include <SPI.h>
#include <WiFi.h>

void setup() {
// initialize serial and wait for the port to open:
Serial.begin(9600);
while(!Serial) ;

// attempt to connect using WEP encryption:
Serial.println("Initializing Wifi...");
printMacAddress();

// scan for existing networks:
Serial.println("Scanning available networks...");
listNetworks();
}

void loop() {
delay(10000);
// scan for existing networks:
Serial.println("Scanning available networks...");
listNetworks();
}

void printMacAddress() {
// the MAC address of your Wifi shield
byte mac[6];

// print your MAC address:
WiFi.macAddress(mac);
Serial.print("MAC: ");
Serial.print(mac[5],HEX);
Serial.print(":");
Serial.print(mac[4],HEX);
Serial.print(":");
Serial.print(mac[3],HEX);
Serial.print(":");
Serial.print(mac[2],HEX);
Serial.print(":");
Serial.print(mac[1],HEX);
Serial.print(":");
Serial.println(mac[0],HEX);
}

void listNetworks() {
// scan for nearby networks:
Serial.println("** Scan Networks **");
byte numSsid = WiFi.scanNetworks();

// print the list of networks seen:
Serial.print("number of available networks:");
Serial.println(numSsid);

// print the network number and name for each network found:
for (int thisNet = 0; thisNet<numSsid; thisNet++) {
Serial.print(thisNet);
Serial.print(") ");
Serial.print(WiFi.SSID(thisNet));
Serial.print("\tSignal: ");
Serial.print(WiFi.RSSI(thisNet));
Serial.print(" dBm");
Serial.print("\tEncryption: ");
Serial.println(WiFi.encryptionType(thisNet));
}
}

Appreciate your help to proceed further on this issue.

I think first off you need to learn to use some of the tools of the forum.
There are code tags ( </> ) that should be used for code and error messages as the forum can eat certain character sequences for lunch.

There are multiple wireless shields for the UNO so knowing which one exactly would be a bonus.
Adding a link to where you got it would be a great help.