Right click a vacant area of your desktop and go to Properties then click Settings. From there it may be enough just to use the slider to change the resolution then see if reducing from 32bit High Colour to 16bit then click Apply and OK your way out. If that isn't enough, go back in and click the Advanced button and click Monitor then check for the option of Refresh Rate and change that to a lower figure.
In addition to saga lout's response (of which is mistaking color depth for resolution), the resolution should be checked as well. This combination of resolution, color depth, and refresh rate is usually a limitation of the monitor, though if you have a low end video card, that can also be the culprit. Resolution and refresh rate are usually the 2 main ones.
A mistrake? Good ness me. I said "use the slider to change the resolution then see if reducing from 32bit High Colour to 16bit". I suppose I could possibly have bunged a comma in after "resolution" but I don't see any confusion. Anyway, too much punctuaiton and one is accused of being pedantic and old-fashioned.