To open IE Developer Tools (see the following picture) in Windows 10 computer, you can use the three methods illustrated below.
Video guide on how to open Developer Tools in Windows 10 IE:
Way 1: Open them by keyboard shortcut.
When the Internet Explorer is launched, press F12 on the keyboard.
Way 2: Open Developer Tools via the Tools icon.
In IE, click the top-right Tools icon, and choose F12 Developer Tools in the list.
Way 3: Open them in the Tools menu.
Select Tools on the menu bar in IE, and then tap F12 Developer Tools in the options.