RE: How to Login Windows 8 after Forgot Admin Password?
The way I know for password reset:
1. Reset microsoft account password online if you signed in with MS account: https://account.live.com/ResetPassword.aspx
2. Ask network administrator if your computer is on a local network.
3. Reinstall Windows OS but this will cause data loss.
4. use third party tools such as ntpassword, opcrack, uukeys, hirensboot, linux live cd: