Make sure you are pressing the ALT CTRL SHIFT keys quickly and in the correct order. I almost sent it back because I didn't press it fast enough and the switch didn't seem to work. I use it with three computers and it has been working great for two months. The only downside is that pressing hotkeys becomes tedious if I have to switch between computers frequently (every few minutes). It would be much better if it had a manual switch as well. However, it is worth the money.
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