How can I change the desktop icon size in Windows 7 without the mouse wheel?

Right click on an empty part of the desktop, and then choose the Personalize command from the shortcut menu. When the Personalization window appears, click the Window Color icon.

This will open the Windows Color and Appearance dialog box.

From the Item drop-down menu select Icon.

Now you can adjust the icon size exactly to your likings and apply the new settings.

It is far more customizable than just the three options from the View menu. You can also adjust the horizontal and vertical icon spacing there.

You can still do it through the right click menu, but you can only pick from three choices instead of the many in-between options:

Start menu → Run → regedit.

Find the following key:

HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics

Modify "Shell Icon Size". The smaller the number, the smaller the icons. You'll have to reboot to see the effect.