Apple Hardware Test (AHT) not progressing on MacBook Air 11" Mid 2013

I've MacBook Air 11" Mid 2013 and I recently clean installed OS X Yosemite on it. The startup was real slow. It took more than 30 seconds to display the apple logo after pressing the power key so I decided to run Apple Hardware Test. BUT THE PROBLEM IS THAT IT WON'T PROGRESS. THE SCREEN DISPLAYS "INTERNET RECOVERY. THIS MAY TAKE A WHILE" AND IT ASKS TO CONNECT TO A WIFI CONNECTION. THEN I SELECTED MY WIFI CONNECTION BUT IT WON'T PROGRESS FROM THERE. P.S. I've never performed Apple Hardware Test before but I've done a lot of research on the internet about it. After selecting WiFi connection, it should prompt me for the password but it won't. It won't progress from here...HELP!!!