NOTE: Before proceeding - Please take a snapshot of your server.
NOTE: These steps show how to install PostgreSQL 16

Create VT Docs DB backup (CMD Admin)

C:\Program Files\visiblethread\vtdocs\VisibleThreadTools
vt-backup.bat  

Stop PostgreSQL service

Services > right click PostgreSQL service > stop  

Uninstall existing PostgreSQL

settings > apps > search PostgreSQL > uninstall

remove (or move to a temp folder) this directory c:\program files\visiblethread\vtdocs\postgresql\14
 

Download PostgreSQL 16.13 Installer

https://www.enterprisedb.com/downloads/postgres-postgresql-downloads

Install PostgreSQL 16.13

Run the installer - point it to the existing PostgreSQL folder c:\program files\visiblethread\vtdocs\postgresql under new directory 16\. make sure to document the new master password, which the installer will prompt you for.
 

Create DB in psql (CMD)

C:\Program Files\VisibleThread\vtdocs\PostgreSQL\bin>psql -U postgres
create database visiblethread;
create role visiblethread with password 'your-db-password';
alter role visiblethread with LOGIN CREATEDB;

NOTE: 'your-db-password' must match the password in /etc/default/visiblethread.env !!

Restore the PostgreSQL 16 DB

cd C:\Program Files\VisibleThread\vtdocs\PostgreSQL\bin>
pg_restore -U postgres -d visiblethread c:\path\to\backup\file.dump

Modify the POSTGRESQL_HOME System Environment variable to point to the new PostgreSQL directory

Press Win → type environment variables → open Edit the system environment variables
Click Environment Variables…
Under System variables (or User variables if that’s where it exists), find POSTGRESQL_HOME
Click edit > select new PostgreSQL directory, likely will be c:\program files\visiblethread\vtdocs\postgresql
 

Restart VT Docs

Restart vtdocs-tomcat service in services.msc
 

Test the application