Help !! please it is really bad

Hello,

at my school we had a charity day, we win stuff ( like that ) and my friend won a pony game ( barbie ) and i
got it for my friends little sister who lives in Oxford, so i went to try it out and it had done something
strange to my laptop such as : the screen has gone bigger, the mouse has gone bigger,everythink has
changed, and the coulor goes differant colours to what it all ready was !! what do i do ????!!!!!!

signed, Gabby Hinton

P.S i would really aprestiate your help :-) x !!