Installing PostgreSQL
 

From PT forum...(can't login there for some reason)

3. After the conversion is done, go to the File/Maintain Database Names window and make the new PostgreSQL database the default database by checking the "Dflt" box next to the name. Click OK to save this change and then close and reopen Poker Tracker.

I installed postgreSQL maybe a year ago but looks like I didn't check the "Dflt" button. What if I do it now? Do I have to convert the access database again (2)? I remember doing this part and it took long.

2. The next step would be to convert your Access database(s) to PostgreSQL, use the Utilities/Convert Database option for this purpose.