if you right click on your desktop and get the display properties menu. click 'appearance' tab, then advanced button at the bottom.
under item where it says desktop click dropdown list and select icon. 'size' on mine is currently 32 which is about the size of a fingernail, so maybe try changing that number if it very low.
if not maybe you need to go to settings on the first menu and change screen resolution.
The easyiest way is to hold down Ctrl key and move your left mouse button forward until you find a readable size format. Reverse mouse to make smaller fonts.
Sorry kookie I misread your post, I thought you meant the size of text. also I meant turn your wheel on the mouse not the left button. Go with the first post from Ankou. I`m going to bed, I`ve had a hard day, g`night.