Password Manager free

Hello, Have been having lots of problems with the eternal-september newsreader via Thunderbird. It was suggested that I delete all my username and password in "Password Manager" and try setting up a new Account for eternal-september news. Where do I find this "Password Manager" where...

So what I want to do is have a Password Manager program: It is a downloadable program (preferably free) that you register an account to and whenever you login with your account and Password it will give you your Username and Password to whatever you fill in. I currently have Keeper to do this...