Windows Vista uses large icons by default in the start menu, and it hides the setting for small icons pretty well. No matter, we’ve located it.

Right click on the start button, and select Properties:

Change Start Menu Icon 1

Then click the Customize button:

Change Start Menu Icon 2

Now scroll down all the way to the bottom. You should see a checkbox for Use large icons, which you’ll want to uncheck:

Change Start Menu Icon 3

And you done!