If you did not change your password, you cannot log in, and when you try to change your password, the security questions are unfamiliar and/or incorrect; your account may have been compromised by a hacker.
Compromised accounts are at an all time high due to viruses and low complexity password which can be easily guessed by the hacker.
I will list a view different options you can take to recover your account.
Try to reset the password using the link, click on forgot password and attempt
Click here>>> Forgot Password
If the reset options do not work then you will have to fill out the Windows Live Account Recovery Form. This is the only alternative solution offered by Microsoft for a free account. Since there is no billing info on the account they unable to validate your identity over the phone and do not offer Live Support. The form will require you to give them a contact email. This will be a secondary email you have access to, Microsoft will then send you a reply about your account to the contact email. If you don’t here is a link to open a free Gmail account.
For the recovery form, click here>>> Windows Recovery
Make sure to fill out as much information on the form as you can. The billing section is left blank since it’s a free account.
It will take a few days to process your form. However you will receive a response and if you provide enough detailed information you should recover the account. Once you have submitted the form you will be provided a PIN and website. The PIN is for a temporary account on the Microsoft private forum site. It allows you to discuss the account in question with their support team. You can ask questions about the account and check the status of the questions and form. It’s a support ticket through their Windows Live Solution Center.
Once they have reviewed the form they then send you instructions on how to regain access to the account to the alternate email you provided on the form.
It may take a few days to process your request, but you will get a response and if you provide enough detail, you should be able to recover your account.
Basically, just follow the steps and fill out as much information as you can and they should be in touch with you. They will give you a pin number and then a link to a private account/forum. Write down the pin number when it is given to you and keep this in a safe place. You'll need the pin to enter the temporary account that will be created for you. The temporary account means they will setup a private forum where you can discuss the compromised hotmail account with their support agent. Your answers to reset or recover the hacked hotmail password or account will be stored in the private forum. You can return to the forum to check the status of their investigation. It's basically just a support ticket through a temporary Windows Live Solution account.
Once they review all the information they will send you instructions on how to regain access to your account to the alternate email address you provided.
This is the ONLY thing you can do. They should answer in 1 or 2 days, but many users have reported that it may take at least a week to get a reply. I understand the frustration but please do it as soon as possible. It's a lot of waiting time, but it is the best they can do considering the tens of thousands of people this happens to, and unfortunately Microsoft does not have phone customer support for Hotmail issues, and sorry to say, it's the ONLY way to get it back.
I understand that this answer may not be entirely to your liking, and I regret being the bearer of information that you really don’t want to hear. But it would be unfair to you and unprofessional of me were I to provide you with anything less than truthful and honest information. I hope you understand that following the above steps is the only way to get your account back...
Please reply back to me with any further questions or concerns BEFORE selecting a negative rating. I will answer your follow ups.