A: Alt+Shift+Z was selected as the default for Windows for enabling the in-game overlay because it is easily accessible during gameplay and a combination of keys that won't interfere with normal gaming.
However, Alt+Shift is the Windows default hotkey set for switching keyboard languages and it is easy to trigger when you are trying to group the entire set of Alt+Shift+Z keys to open Highlight’s IGO.
Some possible solutions to this problem are
• Change the Windows hotkey for changing keyboard language
• Change the key to launch Highlight’s IGO, possibly to Ctrl+Alt+Z)
• Being slightly more careful when using the Highlight’s IGO
• Removing unused alternate keyboards when they are not in use