Error message: “Account does not exist.”

I've had a hotmail email account for 8+ years, that I've always used as a secondary account.  There are valuable emails, pictures, contacts, files etc that I want to continue to have access to.  Now that microsoft has switched to Outlook, I can't sign in at all, using the same email I have always had, because it says it does not exist.  I would like to regain access to my old account.  I had to create a new, temporary account to try and resolve this issue.  It would be great if someone could help me since the people I spoke to in live chat were not helpful at all.  Everything I've tried has just sent me in one big circle.  I just want my old account back and everything in it.