1. First, right click on an empty area on your desktop and choose Properties.
2. In the Display Properties window choose the Appearance tab and click on Advanced - See figure 1.
3. In the Advanced Appearance window, choose Icon from the Item: drop-down list - See figure 2.
4. Then using the up / down arrows next to Size:, select the new icon size you want. Note: you can also set the size manually. The numbers represent pixels. For example, the default shown here is set for having icons display at 32 x 32 pixels.
5. Once you have chosen your new size click on OK.
6. Click Apply in the Display Properties window.