This is a neat taskbar customization hack that lets you increase/decrease the size of the icons on the taskbar to make them better accessible according to your need.
Pasi de urmat
Open regedit and find the following location:
Select the Advanced entry and then right-click on the white space in the right panel and select New > DWORD (32-bit) Value.
Name the new entry as “TaskbarSi” and then open it and change its value to either 0, 1, or 2. Here 0, 1, and 2 mean small, medium, and large, respectively.
You will have to restart Windows Explorer or the PC to see the changes.