Password Manager?
 

What is a Password Manager..?

Well, i think your referring to Firefox's feature that remembers any username and password you want, on which websites you want.

It's basically a menu where you can see all your passwords stored.
So, if you forget a password on a website that you have saved, you can look in the password manager and see the password.

Yes, this sounds risky, right? Yes, if you don't have a master password.

What's a "Master password"?
This is a password that locks the password manager. It will ask you for the "Master password" every time you want to see the other passwords.

This is a mimic of an internal function that exists on the Mac OS since the begining (1983) where you can store all your passwords, even use a global password to activate each password you use on each engine or website. (so if you have a password here that is useful, you can lock that user access until you enter the password of the account itself)

Is there a way to get one on Windows?

it's usually Browser based on Windows... don't know any global version, but you can check on sites like download.com

Umm you could try Mozilla Firefox.
It's one of the best web browsers.
Just google it :)