If losing your past email address is something that will happen, then consider creating a new user account on your computer with the updated email. This way, you won't lose access to your computer, you can follow these steps:
- Select the Start button and then select Settings.
- Select Accounts and then select Family & other users.
- Under Other users, select Add other user and then select Add account.
- Enter the email address of the Microsoft account you want to use for the new account, and then select Next.
- Follow the prompts to complete the account setup.
- Once the account is created, select the account name and then select Change account type.
- Select Administrator and then select OK.