I'd be sure my files are safe on backups then scan with Grif's help. There's more possibilities than malware here and I'll get to those after the link.
Read and do all at http://www.cnet.com/forums/discussions/how-to-remove-pup-option-603542/#post-f742c795-5881-433b-a29b-6d758efe5cd3
If that fails to find or correct it, head to the device manager and uninstall, remove all the keyboards you find in Windows SAFE MODE (how to get to safe mode is widely documented on the web.)
Reboot and re-test.
If that fails, let's look at your machine's SPECCY. Here's how.
If I don't find anything there, you may have to try a factory reset.
Operating System: Windows 10; 64-bit
Problem: The laptop keyboard quit working
Took the laptop to Office Depot for inspection. Office Depot tech said the keyboard was bad and advised to buy a replacement keyboard online from Amazon
Ordered a replacement keyboard from Amazon ($22)
While waiting for shipment, inspected the computer myself and discovered the following:
1. After boot-up, the keyboard would not type.
2. Opened Device Manager; opened Keyboards. It recognized that the laptop keyboard is installed; the device is working properly; and the drivers are up to date
3. Connected a USB keyboard sequentially to every USB drive on the laptop, and it would not type from any USB connection.
4. Opened Device Manager; opened Keyboards. It recognized that a USB Keyboard is installed; the device is working properly; and the drivers are up to date.
5. In order to work with the laptop, opened the On-Screen Keyboard via Start / Settings / Ease of Access / Keyboard / Toggle ON the On-Screen Keyboard
6. After turning on the On-Screen Keyboard, it worked; and lo and behold, both the laptop keyboard and USB keyboard started working again.
7. Turned off the On-Screen Keyboard, and the laptop keyboard and USB keyboards still worked.
8. Restarted the computer, and after restart, neither the laptop keyboard or USB keyboard would work, however, after restarting the On-Screen Keyboard, both physical keyboards started working again.
Continued to use this workaround procedure until the replacement keyboard arrived.
Replaced the original laptop keyboard with the new laptop keyboard. It didn’t work either, until I performed the On-Screen Keyboard procedure, then it worked.
Concluded that this is not a hardware problem, because:
- Device Manager recognized both keyboards as being installed with no identified problems.
- Faulty keyboards don’t start working again just because a software procedure is performed.
What is causing the physical keyboard(s) to not function properly at boot-up?
Why does activating the On-Screen Keyboard make the physical keyboard functional?