PGS Tuning Wizard destroys my login

What does the Tuning Wizard do? The one you can run on PGS ? Does it just touch up the postgresql.conf ? Does it play with other stuff as well?

I am asking because, every time I run the wizard I cannot login with the password I choose when I installed PGS. What is going on? Replacing the generated postgresql.conf with the old to "go back" does not help either.

First time I reformatted my whole disk, and tried install PGS and ran Tuning Wizard again. Same thing happened! 

This time I just uninstalled, and installed PGS again without the tuning wizard and I haven't had any problems since, but I need the tuning! 

The un-installation left some of the Data files behind, which i cannot delete, I have not access to them, but I am logged in as Administrator. 

What is going on!?

Jennifer