I forgot my user password and now I cannot access my Desktop.
For Windows 10, you can download a Windows 10 ISO and burn it to a USB stick. Then use the media to boot into safe mode. Then open command prompt and type: net user username newpassword.
After that, login with the new password you just set.
If it doesn't work, then use this tools to remove the password: https://www.androidphonesoft.com/windows-password-recovery.html