Howtogeek posted a beginner guide about changing the icon view to extra large in Windows 7 explorer

In Windows 7 Explorer, changing the view of your thumbnails and other files is easy by clicking the Change Your View button in Explorer. What you may not have noticed is theres an Extra Large view setting as well.

Change Your View Button in Explorer
When in Windows Explorer you can click the Change your view button to toggle through different sizes of the icons. In this example we are in Details view which gives you more data about the files you're looking at.

After clicking it once we see we have the Tiles View. Clicking it each time will give you a different view including Details, Tiles, Content, List, Large Icons, Medium Icons, and Small Icons.

  Beginner: Change Icon Views to Extra Large in Windows 7 Explorer