Go to your Start menu > Settings > Control Panel > Display

Click on the Apperances Tab and select the arrow in the Scheme field. A cascading menu will appear. Scroll down until you find the desired font size settings, you can preview it in the window. And go ahead and select OK when you're finished.

You can do the same thing by right clicking on the area of the desktop and selecting properties.

If that doesn't work, try changing your desktop area resolution, by right clicking again in the blank area of the desktop, choosing Properties > Settings tab and moving the Desktop area pointer either left or right.