Should I reinstall over current installation?

I just got my Windows 10 computer in Nov 2019 and installed PostgreSQL Jan
this year.

I had a problem with Windows update and when I contacted Microsoft, they
installed a fresh operating system. After that, I was unable to run
postgres from pgAdmin 4 or from a perl program that accessed the database.

The message I got was:

could not connect to server: Connection refused (0x0000274D/10061) Is the
server running on host "localhost" (127.0.0.1) and accepting TCP/IP
connections on port 5432? at pg_01.pl line 8.

I was considering 2 options:

!) Reinstall postgres over the current without removing the current
postgres first.
2) uninstall the current postgres and then install postgres again.

The tables I created in my database are not many and if I lose them doing a
reinstall, I could recreate my database and the tables. I was considering
option (1) as I was wondering if that choice would keep the database and
tables I created this January.

(The database and contained tables are from 'Practical SQL' by Anthony
DeBarros.)

A second question is: When I try to edit anything in pgAdmin, sometimes it
won't let me edit the code. I then refresh the database in the left pane
and then it allows me to edit the SQL in the query pane.

Thank you for any help you may provide.

Chris