How to recover lost admin password for Windows Server 2016 running on virtual box

Question

I installed windows server 2016 datacenter on virtual box for a project and I forgot about it after a few weeks but I now need to access it again but I forgot the admin password. is there any way for me to change the admin password or recover it?

Answer 1

Shutdown VM.

Add some bootable media (real CD/DVD drive, flash-drive, or ISO of such media) with some Windows to VM configuration. Start VM, access its BIOS settings and set VM to boot from added bootable media. Boot from added bootable media, ensure that VM's OS folder is visible.

Then:

Variant 1. Use some third-party software which may create new user accessing OS registry offline (for example, PasswordRenew), create new user with admin rights. Restart VM by common way (do not forget to remove bootable media from VM config), log in as newly created user and reset admin's password.

Variant 2. Start regedit.exe. Attach SYSTEM registry hive, navigate Setup folder in it and edit parameters:

CmdLine=cmd.exe
SetupType=2

Detach hive. Restart VM by common way (do not forget to remove bootable media from VM config). When CMD window opened, execute

net user

Find admin's name and execute

net user admin_name new_password

Then run regedit.exe, navigate HKLM\System\Setup, restore keys values, and reboot.

Log in using inserted password.