Upgraded one of my laptops to Windows 10 and immediately locked the admin account. Googled and found a bunch of suggestions using the Windows 10 install CD? As most other people I upgraded via the Windows 10 upgrade notice that was bugging me for months. So how do you get back into a Windows 10 machine you locked your self out of?
Before the upgrade I decrypted my boot disk and uninstalled the old Truecrypt install I had on there so accessing the disk wasn't an issue. If you have full disk encryption enabled you will not be able to use this method.
Prepair Hiren's BootCD & Boot
Hiren's BootCD contains a miniXP version that is perfect for this. Download it and follow the instructions in Launching Hiren's BootCD from USB Flash Drive. They have a really good step by step guide there. Once that is all done restart your computer from the USB drive and select "Mini Windows XP".
Prepare for password reset
Once you are booted up locate your windows boot drive. In this example I will use E:\ as the Windows boot drive. Locate the following file:
Rename it to:
Then make a copy of:
And rename it to:
You can also do this via the command prompt like this:
move d:\windows\system32\utilman.exe d:\windows\system32\utilman.exe.bak copy d:\windows\system32\cmd.exe d:\windows\system32\utilman.exe
Then reboot your computer and let it start Windows 10.
Change the password
Once at the login screen press CTRL+ALT+DEL and click the icon for the "Utility Manager" in the lower right hand corner. This should launch a command prompt with admin rights. Just type in the following commands:
net user <username> /add net localgroup administrators <username> /add
This will add a new account to the local admin group. Then close the command prompt and login with the new account, the password will be blank.
Delete the C:\Windows\System32\utilman.exe and rename the utilman.exe.bak back to utilman.exe