1. Right click an open area of the Taskbar
2. Select Properties
3. Select the Start Menu tab
4. Tick the “Start menu entry and click the “Customize” button to the right.
5. Scroll the list until you find the “Run command” entry.
6. Place a checkmark in the “Run command” checkbox.
7. Click OK.

The Run command will now appear in the Start Menu.

Alternately, you press the Windows Key + “R” on your keyboard and it will pop right up.