If you forgot your Windows 10 Offline user password you can reset the password by using a windows 10 installation USB stick and some simple hacks.
Good to know is that all the users encrypted saved passwords being reseted so you going to be needed to login again on all applications.
Start with setup a Windows 10 installation USB-memorystick so you can boot on it.
Boot on the USB and when the first prompt for the Windows installation shows, where you select langauge and keyboard layout and time and currcency format press SHIFT + F10 to open a command prompt.
Now we need to replace utilman.exe with cmd.exe, before you do this, you should make acopy of utilman.exe so that you can restore it later. Note that you can only restore this file if you boot again from the Windows DVD. Windows 10 is usually installed on drive D: if you boot from a DVD. You can verify this with “dir d:\windows\system32\utilman.exe.” If the system can’t find utilman.exe, try other drive letters.
move d:\windows\system32\utilman.exe d:\windows\system32\utilman.exe.bak
copy d:\windows\system32\cmd.exe d:\windows\system32\utilman.exe
net user <username> <password>