Go to the Create Account page from Microsoft, click "Get a new email address" and enter possible email addresses until you find one that isn't taken. Create password when prompted to do so, and then enter your first name and surname on the next page.

On the View tab, select View settings. Select Accounts > Email accounts. You can now add a new account. Under Email accounts, select Add Account, and select a suggested account from the dropdown menu or enter a different email address. Click Continue.