it looks like you are trying to run as user 'localhost'.
google on how to set passwords for mysql accounts. i cant remember off of the top of my head, but i think this should get you in to mysql (this is what i use, but i am using linux)
mysql -u root -p -h localhost
try that, and if it asks you for a password, just hit enter. if i remember correctly, it will let you in since you havent set a password yet.
try that. hope it helps.