Handy FAQ (Frequently Asked Questions) on Passwords in Windows 8.1 (also applies to Windows RT 8.1 BTW):
- I don't have my password. What do I do?
- Can I sign in without a password?
- How do I create a strong password?
- How do I change my password?
- Does my Microsoft account password affect the password on my email account?
- How do I sign in with a picture password?
- How can I remember my password?
You may also find the following links useful:
- What to do if you’ve forgotten your Windows password.
- Get back into your Microsoft account if it's been blocked or hacked.
- Can I sign in to Windows without a password?