HP Laptop adding random strings of "4"

kimprather912

Prominent
Nov 15, 2017
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510
I'm working on a laptop that the user thought had been hacked because every time he uses it, it will start putting long strings of 4s in search boxes, notepad files, login fields, etc.

I booted it up and the problem occurred offline, so I'm pretty sure he's mistaken about the hacker. I have since scanned with Sophos antivirus, malwarebytes, super antispyware, and the Sophos virus removal tool. They all found what you would expect from random browsing and removed it. I also ran Hijack This and did not see anything out of the ordinary.

It will work fine for a while, then I will click the start button and it will jump to a search box and the 4s will start scrolling, or I'll open a web browser and the 4s will start scrolling across the address bar. Once that happens the touchpad will stop working but I can use an attached usb mouse.

It doesn't look like the keyboard is malfunctioning in any way and all hardware diagnostics I have run are all okay.

This is an HP Pavilion laptop running Windows 10 Home.

Any ideas about what else to try, or should I just tell him to order a replacement keyboard?

Thanks in advance.
 
Solution
If you are willing to put in the effort. Disconnect the built in keyboard. Then plug in a USB keyboard and see if the problem still exists. But is sound like a keyboard issue to me.

You can also try removing the 4 key. Turn off the computer. Then dampen a Q-Tip with rubbing alcohol (squeeze out excess alcohol). And try to clean the keyswitch.
If you are willing to put in the effort. Disconnect the built in keyboard. Then plug in a USB keyboard and see if the problem still exists. But is sound like a keyboard issue to me.

You can also try removing the 4 key. Turn off the computer. Then dampen a Q-Tip with rubbing alcohol (squeeze out excess alcohol). And try to clean the keyswitch.
 
Solution