Dell 5570 Keyboard issue

Connect an external USB keyboard and try that for a while. If the issue also occurs with the external keyboard, then the issue is something in Windows. If the issue does not occur with the external keyboard, then it's likely a hardware issue with the onboard keyboard and it may need to be replaced.

Here are some other things to try:

• Try a power reset (unplug AC adapter, disconnect battery, hold down power button for 30 seconds to discharge flea power. Then connect the AC adapter and try it).
• You could go into Device Manager and delete the keyboard driver. Windows will install the latest.
• Use the keyboard troubleshooter. Troubleshoot settings | Additional troubleshooters | Keyboard
• Try in Safe Mode to see if the issue occurs there.
• Try the Windows on-screen keyboard. If on-screen keyboard also exhibits the issue, it could be due to corrupted system files. Run SFC (System File Checker) scan on your PC to repair those files.
• Try in Linux (by booting from a flash drive with Live USB install of Ubuntu, Xubuntu or other)

Dell keyboard troubleshooting guide
https://www.dell.com/support/kbdoc/en-ca/000131432/keyboard-usage-and-troubleshooting-guide

If it turns out to be a hardware issue, you can buy replacement palmrest/keyboard assembly from Parts-People, or use their part number to search online for other sources.

You might be experiencing this issue because the current keyboard driver is not playing nice with the new Windows update. As such, we recommend that you check Dell's website for the latest keyboard driver for your laptop. If the issue persists while using the latest driver, try using an older one.

A configuration error can also cause this issue. To isolate the cause of this problem, we suggest that you run the hardware troubleshooter. This tool can help diagnose and fix hardware issues. Here's how:

Click Start.
On the search bar, type Troubleshooting, and click on Troubleshooting from the results.
Click Hardware and Sound.
Under Device, click Hardware and Devices.