Hi Ralf,
I had to use the task manager to stop the pgAdmin counting seconds.
I would not use the new pgAdmin 4 at the moment, it seems to still have bugs.
However, they just announced a new version with 40 bug fixes, see here:
https://www.pgadmin.org/If that does not help, it may be more easy to install a postgres version with an older pgAdmin, or install the former pgAdmin separately, while I do not know if pgAdmin3 is compatibel to the latest postgres. postgres experts should know that, maybe you ask in a forum like stack overflow.
pgAdmin itself has not a forum but a mailing list, as far as I know.
For me it was a big help to use pgAdmin 3, as I did not like to type in commands at a DOS prompt for simple tasks like backup and restore.
You can google "postgres tutorial" and you get a lot of links, like
http://www.postgresqltutorial.com/.
However postgres is in its heart SQL, and postgres itself has a good documentation:
https://www.postgresql.org/docs/You might also want to google "pgadmin tutorial"