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:

Then click the Customize button:

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

Ahh, much better, especially if you pin your favorites to the start menu: