When the CPU is under heavy load, sometimes GoToWindow doesn't show up or skips a "Tab"

[christianrondeau]

I don't think there's a way to completely avoid that. Windows shuts down the ability to response to keys after a very short time (see LowLevelKeyboardProc callback function on MSDN).

What has to be tried is launching a separate thread that does nothing else but checks for the hook. That'll avoid callback happening at the same time as process events.