
When your Windows 10 Password is forgotten (lost), it is practically impossible to use the device, neither will you be able to install any application (program) nor Windows Updates, etc. The process of resetting the password is tedious and Microsoft has decided to harden the entire process. For how to reset the windows administrator tool, see the link. Below are the various methods to reset a Windows 10 device.
Via Password Rest Disk: This is one of the ways to reset your Windows 10 password that resides locally and not on Active Directory.

Note: In this method, you need to create a Windows 10 password reset disk before your password is lost.

Via The Command Prompt: This method requires you to have access to the command prompt of the device or remotely access it and perform this operation. In this case, special permissions are required to be able to perform this task. This method was already discussed here, kindly see how to reset your built-in Windows Admin password.

– Via Microsoft Online Password Reset: For those that use Microsoft account for logging into Windows, when your Microsoft account password is lost, simply visit the Windows Live password reset page (Microsoft website) to reset your password. Here is the link
Via Microsoft Diagnostics and Recovery Toolset (DaRT): This is a toolset from Microsoft that helps IT professionals recover the computers that have become unusable. Boot your computer with DaRT Recovery CD and then launch the built-in Locksmith Wizard tool, it allows you to reset the Windows 10 password of any local account.
– DaRT helps to troubleshoot and repair Windows-based computers. DaRT 10 requires thorough planning before you deploy it or use its features. For more information on Dart, see Microsoft Desktop Optimization Pack [MDOP], and the following link

DaRT 10 is a vital part of the MDOP, a dynamic solution available to Software Assurance customers that helps reduce software installation costs enables delivery of applications as services, and helps manage and control enterprise desktop environments.
Other Password Reset Tools
– PCUnlocker: PCUnlocker allows you to unlock any Windows computer that you were locked out by a forgotten password. It is a bootable image that can be written to a CD or a USB stick using the freeware ISO2Disc. After booting from PCUnlocker Live CD (or USB), you can view all local accounts for your Windows 10 installation.
– Hiren’s BootCD PE: Hiren’s BootCD PE (Preinstallation Environment) is a restored edition of Hiren’s BootCD based on Windows 10 PE x64. Since there are no official updates after November 2012, the PE version is being developed by Hiren’s BootCD fans. It includes the least, best, and updated free tools used in Hiren’s BootCD. It is being developed for the new age computers, it supports UEFI booting and requires a minimum of 2 GB RAM. Here is the link to the Hiren download.
While resolving this issue, there were some methods I did not discuss, see this link for more information.
I hope you found this article useful. If you require additional information, please let me know via the comment session.