Hotmail account says my account doesn’t exist?

Every time I enter my email address it says that this account doesn't exist. I made it within the last month for Netflix and when I logged into Netflix (after learning that microsoft thinks my account doesn't exist) that it still works perfectly. I need to get into this account ASAP as my mum bought a new laptop and gave it the wrong email address (this one) thinking that it was my "main" email account. Thanks.