Usually a hacker will take pains to hide their activity, what you describe doesn't sound like hacking to me. My first guess would be a problem with the keyboard, especially if an external USB one works properly.

You might have a stuck key - try hitting every key at least 4 - 5 times and check none are sticking.

Has the keyboard ever had anything heavy dropped on it, or liquid spilled on it?

You could try gravity-cleaning it:

- put down a sheet of paper to catch debris
- turn your laptop upside down over the paper and hit it lightly in different places across the back/under the keyboard, 20 - 30 times
- you may be amazed at what falls out - I've seen staples, paper clips, lots of food particles. Those can jam the key mechanisms, cause short circuits etc.

You can also try a can of compressed air, but if you do that I recommend doing it upside down as well so debris isn't driven further into the keyboard mechanism.

Dells usually have built-in hardware diagnostics you can access during a cold boot.

>>https://answers.microsoft.com/en-us/windows/forum/windows_10-other_settings-winpc/cannot-login-my-windows-10-computer-cause-the/ab1b3b6c-bfcd-49f9-b16d-762a47959e22
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>I read a few of these but this is not my situation.
>
>I use PIN number to open Windows on that laptop. If I put external keyboard, I can type and login and I was even able to do one Zoom class. I used different social media (not a FB) to communicate with one fellow instructor who gave me that link. I left computer and that other social media open for ~5 min. and then I returned I found that one character letter started appearing on its own again in that window as well. After that I shut down that laptop again and not doing the class which I wanted to do. I believe it's a clear indication of hacking :( I also closed all browser windows, but I'm not sure how much information was already gathered.