Try one of these malware-removal guides:
https://www.bleepingcomputer.com/virus-removal/remove-prime-updater-primeupd-pup/
https://malwaretips.com/blogs/remove-prime-updater-adware/
Also consider enabling Windows Defender’s built-in Potentially Unwanted Application blocking (PUA Protection).
Right-click on the Start button and launch Windows PowerShell (Admin); and then copy, paste, and enter this command:
Set-MpPreference -PUAProtection 1
Limited Periodic Scanning must be enabled for this when a third-party AV app is installed:
GreginMich