How do I enabled Windows 10 to be able to run PSQL etc

Hello experts,

Ever since I found out I have a different versions of Postgresql residing in my PC, I have deleted the old version - 10
and7 altogether and installed version 11.
 

So, all look good except that I can't use PSQL at all.

Then, I found out that there is a security tied to using PSQL in Windows 10. However, I tried to alter the setting for
DESKTOPuser to Full-Control I can't find a way to do it. Neither can I find anything from the internet.
 

Please advise how do I alter the setting so that I can use PSQL freely.  

I had tried to use runpsql.batch after reading a Stackoverflow user advice.

But, when I tried to do some psql comments, it doesn't work.

What is that comment you might ask - which is my next problem - this comment is to allow me to merge a table which I
havecreated in PGAdmin 4 into a schema - membership which has 3 tables there already.
 

The thing is that I found that the table which I have created, it is not able to appear under the schema - memberships.
But, when I used runpsql.batch, and use /l , it will show up as a table but under postgres.
 

Now, in my PGAdmin 4, I did not create a user name either, it is also using postgres as user name so why is the table
notappear as a table even after I refreshed.
 

So, I hope someone can tell me the solutions to the above problem.

Thanks & regards,
Karen