If you suspect someone is viewing your Hotmail or Outlook.com email account without your consent, we recommend that you change your password. This will prevent the theft of your personal information and the use of your account for sending spam, or other illegal purposes.
Change Email Password for Microsoft Hotmail or Outlook.com
To change your password, log in to your Hotmail or Outlook.com email account, click on your profile picture, and select View account. Next, click Change password, enter your current password, and click Sign in. Then you must verify your identity. To do this, enter the code that will be sent to your mobile phone or to your alternate email account and click Send code. After verifying your account, enter your current password, the new password, and confirm it. Finally, click Next and an email will be sent confirming the change of the password.