Dude they are called Taskbar Thumbnails
Here is how you can do this:
1. Log in as an Administrator into your Windows 7 computer.
2. Click the Start Menu and type “gpedit.msc” in the search box. Hit enter to open the Local Group Policy Editor.
3. Navigate to User Configuration –> Administrative Templates –> Start Menu and Taskbar.
4. On the right side pane scroll down to the end of the list to find ‘Turn off taskbar thumbnails’ and double click this entry. In the following Setting window (see image below), select Enabled and click OK.
From now on whenever you hover your mouse over an icon in the Taskbar you will only see text tooltips.
found it here
Code:
Hidden Content you run a modified OS this may not work but give it a try
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