PC typing an asterisk after every letter...

Well, I'm happy to say that I did ntot have to go to the extent of reinstalling Windows, thank god.I ran some other scans on Avira and it found what and wherever it was and fixed it. YAY!!

Thank you for your help. Despite it not exactly leading to the solution, I still appreciate you taking the time to answer. 

Hi,

I think your PC may be infected by a malware... Download Malwarebytes and run a scan of your system.

Let us know how it goes.

As a malware doesn't seem to be the cause of the problem and taking into account that you've already tried to reinstall the drivers and restoring your system to a restore point, I invite you to try the following:

• Go to Settings > Ease of Access > Keyboard and disable Sticky Keys, Toggle Keys and Filter Keys.
• Boot in Safe Mode and test your keyboard to see if that changes anything. If you keyboard works, try uninstalling recent software you may have installed prior the keyboard problem.
• Open Command Prompt as admin and type sfc /scannow then press Enter to run the System File Checker. Corrupted system files will be repaired with this command.
• Check your BIOS settings - try resetting the options back to default. If a firmware update is available, try updating your BIOS.
• If your keyboard still won't work properly, reinstall Windows without data loss. The instructions are described in this article.

Good luck