You could have the Enterprise version which requires a volume license for businesses and must be renewed. Check your version by typing winver in the Run box.. That KMS activator is for Enterprise not OEM windows 10 Pro which you should have. Did someone ever change your windows installation?  If you originally activated Dell's windows 10 pro and connected it to your Microsoft Account you can use Create Media Tool to download the right version that matches your license. Then do a custom clean install.  [URL]
I have Dell 3470 i3 8th Gen desktop 1TB HDD & 4GB RAM with Original windows 10 Pro. After 5th month from the date of purchase, windows says "licence will expire soon". My friend advise me to run KMS Activator, but I paid extra money for Original Windows 10 pro than why i run activator? Now what is the next step? Someone Please help me Email: 
Windows 10 Pro says "Licence will expire soon"