STEP-1: First get the Url of video you want to watch. As shown below. http://www.youtube.com/ watch?v=

4Xkh6j7RMqk

STEP-2: Then copy the

Video Id

. For above link video Id is

4Xkh6j7RMqk

STEP-3: Now paste the

Video Id

in the link given below. http://www.youtube.com/ v/

VideoId

?fs=1 Replace

VideoId

with the Id you copied in Step 2
STEP-4: Now the url will become as shown below. http://www.youtube.com/ v/ 4Xkh6j7RMqk?fs=1
STEP-5: Now enjoy..!