The system should log you in automatically with no need to enter a username or password. However, there seems to be a problem affecting a few people where this doesn't work. At the moment, we're not sure exactly what's causing it and we haven't been able to replicate it here.
It's possible that there are a few faulty discs. The MD5sum of the disc I have that works is 1c9747758906617adf73a6b266f325f1 . If yours is different, contact firstname.lastname@example.org
, they'll be able to send you a new disc.
It's also possible that there is a problem with some hardware configurations. If you have another computer available, could you try it on that and let me know if it works please?