Vista Mail Program

I don't know what happened, I shut down my computer like normal and when I
started it back up, now windows mail no longer remembers my mail account
username and passwords, it prompts me every time that I start windows mail to
enter my username and password to login to my isp pop servers.

I've gone into the account settings and the username is there and I've even
re-entered the password making sure that remember password is checked, but
once I shut down windows mail, and start it up again it again asks me for my
username and password for each pop mail account that i have in it.

And vista has also now forgotten all of my usernames and passwords
associated with web forums and login sites as well.

Any clues on this one?

Thank You Bob H.