Can't update or re-install

The problem is that I can’t update or reinstall my avast. There is 198 days license left and all but it just keeps saying that I need to update and when I try, it doesn’t do anything. I tried also to uninstall it so I can then install it back. But when I tried it said that I need to be admin user… and I am one.
When I just try to install newest version it says that

“Error reading product data from “C:\Program Files\AVAST Software\Avast\setup”. Setup cannot continue.”

after that it says “An errro 0 (00000000) has occured. Last performed operation was: spawning.”

Is there anything I can do or do I really have to format my computer so I can update?

uninstall using avast removal tool…reboot and install latest version

the tool is found at avast.com > support > downloads