Windows 10: Reset Local Account Password using Install Disk

Windows10ResetLocalAccountPasswordUsingInstallDisk.md

Windows 10: Reset Local Account Password using Install Disk

Windows 10's install disk is itself bootable and can help us reset the password on a Local Account (not a Microsoft account) of the existing Windows 10 install.

This document doesn't exhaustively detail how to perform every step. It also doesn't discuss consequences of changing a Windows 10 account password, especially when encrypted filesystems are in use. Its intended audience is the user who has researched both (see Credit below as a starting point).

This document also assumes that the existing Windows 10 install is healthy.

This process exploits the fact that our existing Windows 10 install allows us to execute Windows\system32\Utilman.exe before/without logging in, by clicking on the login screen's icon for Ease of Access (formerly Utility Manager). By renaming cmd.exe to Utilman.exe before booting our existing Windows 10 install, we can later get a Command Prompt in the existing Windows 10 install before/without logging in. From this Command Prompt, we can reset an existing Local Account's password (or create a new Local Account and add it to the local Administrators group, etc).

• Boot to Install Disk and acquire a Command Prompt -- Shortcut: [Shift+F10] at the first prompt
• Navigate to the volume of the existing Windows 10 install -- wmic logicaldisk get caption lists all volumes
• Navigate to Windows\system32
• Backup Utilman.exe and cmd.exe -- copy Utilman.exe Utilman.exe-orig -- copy cmd.exe cmd.exe-orig
• Copy cmd.exe over Utilman.exe (last step below reverts this) -- copy /y cmd.exe Utilman.exe
• Boot to Safe Mode[1] of existing Windows 10 install
• Click on the login screen's Ease of Access icon -- Command Prompt immediately[2] appears
• Issue commands against the existing Windows 10 install -- net user x y, where x is the existing username and y is the new password
• Only once all is satisfactory, boot again to the Install Disk and restore Utilman.exe -- copy /y Utilman.exe-orig Utilman.exe

With this command prompt, we can issue against the existing Windows 10 install whatever helpful commands we like. The syntax above lets us reset the password on an existing Local Account, but another net syntax will add a new Administrator user, if that's called for.

Credit: Reset a Windows 10 password (4sysops.com) covers these steps, but the Safe Mode bit is buried in the comments.

[1] Actually, the "Disable early-launch anti-malware protection" Startup Setting will suffice, if that's preferable. On workstations without Windows Defender or other malware protection, Normal Mode might work.

[2] If clicking the Ease of Access icon does nothing, Windows Defender has likely quarantined the modified Utilman.exe (addressing some Windows Defender alerts upon next logging in to the existing Windows 10 install will fix that). If you haven't tried Safe Mode[1] yet, try that.