Can't access the game anymore

I have not logged on in a couple days, and can no longer access the game.

I keep getting the bad .pak file message

Did you install patch 2.60b, but forgot to patch the game to 2.60 before? You need to reinstall the game.

Take out your etkey from the folder called "etmain", that's where your XP is saved, then go to http://etkey.org/pages/enemy-territory-full-install-windows.php

Uninstall your ET, make sure nothing is left from the old folder, and then install the version that is under that link. When it's installed, you can switch new etkey with the old one that you saved before. (That's if you care about XP of course).

Seemed to solve the connect problem, but mt etkey won't take for some reason, and I am prompted to create a new profile

You have to create a new profile, since it's new installation. When you do, make sure to click "Enable punkbuster".
It's crucial for XP to work.