To change the size of the on icons on the desktop, you can use this tweak to make them larger, The default setting is 32
If you change this to 36, your icons will be slightly larger, the higher the number, the larger the icons will appear.
First you want to go to Start > Run, and type Regedit. navigate to HKEY_CURRENT_USER > Control panel > Desktop > WindowsMetrics. Click on the WindowsMetrics key and choose File > Export from Regedit's menu. Save the .reg file as windowMetricsoriiginal.reg. In case you don't like the changes, you can double-click on this file to restore the settings to their default value.
Windows Registry Editor Version 5.00
"Shell Icon Size"="36"