I think the best option is to go to Program and files -> Select PostgreSQL and “Uninstall”.
Uninstaller will ask you if you want to uninstall the whole application or only individual components. Select individual components and then select pgAdmin.
This will uninstall pgAdmin from PostgreSQL directory.
From now, install the latest version pgAdmin only from official website which will install it into: C:\Program Files (x86)\pgAdmin 4\v4