How do u change your screen size on a gateway computer?

i need help!!after i was playing a game my screen changed cant find how to make it normalHow do u change your screen size on a gateway computer?
If you have XP: right-click on the desktop and then left click on Properties from the menu that appears. The display properties dialogue box will appear, click on the settings tab at the top right of the box. To change your resolution slide the bar along to the resolution of your choice and then click Apply.



If you have Vista: right-click on the desktop, from the drop down menu click Personalize. In the Personalize window click the Display Settings link. Move the slider to the resolution you want and then click Apply.