User blog comment:The Index 2.3/Hi mass effect wiki I have a problem with my game you may find interesting/@comment-26686429-20120228074120

You should be able to use the movement keys on the keyboard to move the selection to the code segment you need, and then select with the use key. No mouse should be used.

Unless you're talking about the hacking minigame that looks more like a circuitboard diagram - in which case you should be able to move your mouse to select the matching symbols.

If this doesn't work - try messing around with the game settings - or perhaps reinstalling the game altogether.