Okay, so I got my new rig the other day, and it runs like a charm, but whenever I try to play minecraft, it says "login failed". On the minecraft site, it says that my username/password is incorrect too! I have no idea what's going on, is anyone else having this problem?
Are you still using your minecraft username to try to login, if so you will have to migrate that account to a Mojang account, which uses an e-mail address as the login.
Thanks, I had a bit of trouble with passwords and stuff too, as I signed up with an old email address ages ago, and I'd forgotten the password for that email address. It's all working now though :)