Please list Dell model number and version of Windows. Example: Alienware m15 R3, Windows 10

How to find the product model of your Dell computer

In the meantime, I suspect message could be a Trojan or Malware. You ran computer Anti virus software to check for viruses ? I also suggest using System File Checker on the computer to check for any corrupt files that could be causing the message. 

Use the System File Checker tool to repair missing or corrupted system files (microsoft.com)