Why is my keyboard/mouse touchpad not working?

I use my mom's ASUS laptop on a regular basis. I've dropped it maybe once, but that was a while ago, and nothing was wrong. Yesterday, the keyboard started behaving oddly, and half the keys aren't working. I plugged a keyboard in via USB and that one works, but still, I'd prefer not to use it in the future. Today, my mouse touchpad (on the laptop) started also acting odd. I can right click, but can't left click. The mouse is on the screen. It worked again, and now its not working again. I had malware a while ago, but I got McAfee, so I don't think that's it. But could it be a virus/malware? How do I fix it? This is my moms computer, I can't afford to buy her a new one.