I have had the same hotmail account for years and have been active on it daily.  However, today I tried over and over to log in and just continued to get the following message: "That Microsoft account doesn't exist. Enter a different email address or get a new account."

I REALLY need to get back into that account, and I'll even upgrade to the paid version if needed, but i want to know what's causing this and how to get it back ASAP.

The email address is {removed}[at]hotmail.com

Any help is appreciated, thanks!