Not Able To Log Into Account On New PC (huh?)

So a while ago I got a new PC and decided to set up FF11 today

Everything went smoothly up until after I downloaded the latest version of POL.

I filled in my information (said I was already a member of POL), but when I try to log in it says my username or password is incorrect.

I have double-checked everything and it should be ok...?

Could someone be so kind as to help me out with this last crucial step? I don't get what I'm doing wrong and google-searching is not helping.

Have you verified your POL ID and PW as well as your SE ID and PW are correct by attempting to sign into your account from the Square Enix Account Management website?

There's like 14 different passwords for that crap, you have one wrong somewhere, probably one you had set to auto so you never had to enter it.

*minor update*
So I logged into the SE account system and I got in np. All my info is there, my character is active, payment method. Everything

And no, it's not something silly like Caps Lock :/

Ok just to be sure I'm not doing something stupid:

Member Name: That would be my character name correct?
Playonline ID: 4 letters and 4 numbers
Playonline password: the password for when I log in; it's the same password that I use to log into the SE account (or do I need to use something else here?)
Square Enix ID: The ID used on the SE acount website

member name doesn't matter, you can change it, it's just there to differentiate between accounts on the computer. yes to playonline ID, playonline password is not the same as the one you use to log into member site. It's completely different and there is a possibility you had two, because POL is stupid. That's one you probably had set to save and never had to enter in the past 20 years.

square enix ID is the one you use on the member site.

Depends, your Playonline password is a separate password from your SE Account pass unless you are positive you used the same password for both. For example, my Playonline password is different than my SE pass since the SE account linking didnt exist back when I first made my account (if I recall correctly).

Member name doesn't matter AFAIK, that's just a local nickname for the profile on the computer.

7 million virtual hugs for you!
So it WAS the playonline password that had to be something else. I was so confused...
But I got into POL; hooked up the account (everything works it seems!)
So now I'm updating FF11. That could take a while :P
But thank you so much!!!!

iv had to deal with that same issue from new installs or different comps so many damn times myself..