Background help?

Hello,
okay, so i got a new mini sony viao laptop, that has windows 7. i got it with my christmas money, it was only like.. 470 all together, so when i got it, i first wanted to changed my background. so, like normal laptops/computers, i right clicked, and go to the last link thing, to click personalize, or whatever it says.. well, my mini sony viao laptop windows 7 DONT have it?? ive went to the help, and clicked the video it had to help me with, and on hte video, it has personalize, but on mine.. it dont? is it just my computer? do i need to sent it back? PLEASE HELP, i want to change my background desperlaty.. OH, and when i go to paint, and make somthing, and go to where it says you can put it as your background, well, if i click tile, full, or center.. and when i click one of them, it just changed the style of the background, but its still the same, just.. differnt shape. but still same picture that it had origonally. has anyone else had this problem??