Full Convert by Spectral Core is a robust tool for converting databases from one format to another. The following instructions will walk you through using Full Convert to convert a Postgres database to MSSQL.
Launch Full Convert
Click New database copy project in the upper left.
Select PostgreSQL from the option list (green arrow below)
Enter your connection information to the Postgres database you're converting (green square section below).
Click Next near the center top of the window.
Select SQL Server from the option box near the top, indicated by the green arrow below.
Enter the connection information to your target database (green square below). If you type the name of a database that doesn't yet exist on your server you will have the option to create after clicking Next.
Click Start Conversion be begin converting your Postgres database to MSSQL