Nostalrius Begins - Quality wow vanilla realm (1.12)

I have recently upgraded to a new pc and I tried loging into my account... with what I would usually use as account name and password. But i am unable to log in...

Is there anyway I can find out what my old account name is? I'm pretty sure I can figure out the password once I get that info. My old company is not available so I can get that info off it.

Thanks, in advance.