It's either a hardware issue or a software issue.
I'd start with downloading, burning (to DVD) and booting from a Linux disk. If it behaves normally then, it's a Windows issue. Then go back to factory conditons. If it behaves just as strange in Linux it's a hardware issue, and then it's time for a new laptop.
Okay, so I've got a Acer laptop, cirka 5-6 years old. It has recently started to do things on its own, like expand a Youtube video, create folders, etc, at random. When I go to create a folder, I have to type in the name really quickly, as when I type, it'll stop typing, & act as if I clicked somewhere else, or left the folder. I also can't watch any video online in fullscreen, since after about 5 sec, it'll automatically minimize the size. I have done countless virus searches, but nothing comes up. I don't really know what else I can do, as I am not great with computers.. It hasn't broken my laptop so far, so it's nothing horrible, it just gets really annoying.. Any help would be appreciated!