My keyboard isn't working right!!??

Someone please help me—I have no idea what is happening to my computer. I can't even type on it properly, so I’m stuck writing this from my laptop...

I have an eighteen-month-old at home, and my wife told me that while I was out at work today, the kid was banging all over my keyboard. Apparently, something went haywire with the system...

The whole thing started when I realized my desktop orientation was flipped sideways; I managed to fix that using the "landscape" setting, but the keyboard itself is absolutely losing its mind:

Instead of opening the taskbar, CTRL + ALT + DELETE just shuts down the computer. Pressing the number 4 key turns the machine off entirely—for heaven's sake, help me here... The letter C doesn't work at all, the command key (with the macOS icon) SHUTS DOWN THE COMPUTER instead of pulling up the Start menu, and hitting the down arrow rotates my desktop screen to the left, so I have to keep flipping it back. The up arrow puts the PC into SLEEP MODE, and hitting ALT just launches the calculator... WHAT IS GOING ON????? What could a toddler possibly press while slamming the keyboard to cause this level of chaos? I need this computer urgently and right now I practically CAN'T USE IT AT ALL!!

Look, try plugging in a different keyboard to see if the issue persists. If you run a system restore back to yesterday and everything returns to normal... well, then you have your answer. But if a second keyboard works perfectly fine without any glitches, then your current one is officially dead in the water.