With Windows 10, if you have forgotten your login password, you have a few potential options:
1. If you set up Windows using a Microsoft Live email address, you can reset the password at http://www.live.com
2. If you set up an Offline account, you can use a password reset drive if you created one when you were previously logged into Windows.
3. If the above two options aren't available, you'll need to reset the PC back to a factory default setting, with a fresh copy of Windows. We have a built-in restore method on all of our PCs (see below for instructions.)