changing the refresh Rate in windows vista

in my computer architecture class were supposed work on exercise 3.1 changing the Refresh Rate in windows vista. Refresh rate is the number of times a display image is repainted or refreshed per second. the refresh rate is expressed in hertz. a refresh rate of 75 hz means the image is refreshed 75 times in one second. these were some of the steps that I had to go throw to change the refresh rate in window vista this is different in window xp. 1.) Right-click a blank portion of the desktop. 2) click personalize 3.) there should be a big screen that says personal appearances and sounds with a list of icons click on the display setting link. 4.) click on the advanced setting button there should be a picture of two icons with 1 and a 2. 5.) click monitor tab you have a choice of picking 60 hertz or 70 hertz what ever you prefer and thats how you changed the refresh rate using windows vista. According to my text book A+ computer study guide it says just because refresh rates appear in this dialog box does not mean that the associated monitor will be able to handle that rate.