Can't install Postgres version 18 - Mailing list pgsql-general

Hi

I had installed Postgres version 18 earlier on my PC, but I want to start over, and remove all of the DB's I have made. I couldn't figure out how to do that, so I googled and was told that I should uninstall postgres, stop the service in the task manager, and then delete the folder under C:/Program Files. AFter that I should restart the PC, and everything should be gone, and ready to be reinstalled. I did that, but each time I am trying to reinstall it, then it doesn't make any folders under Program Files, so the service can't be started. It just give me this warning 

 

If I try to reinstall it again, it tells me that it is already installed, and asks me if I want to make a change, repair, or uninstallation. I have tried to choose that it should install the docs also, and then it creates the folder under program files, but it only contains the docs nothing else.

I have tried to restart the PC, reinstall it and tried google how to solve this but no solution yet. 

I hope you could guide me the right way.