Reset PC without Admin password

[Salmon Trout]

Raymond Chen's link in The New Old Thing Tips section (worth browsing, IMHO) is subtitled: "What I reboot three times is true".

https://blogs.msdn.microsoft.com/oldnewthing/tag/tipssupport

Suppose you found a (Windows) PC in a closet and you want to reset it, but you forgot the administrator password. What can you do?

https://blogs.msdn.microsoft.com/oldnewthing/20161206-00/?p=94865

There is an emergency reset button that you can activate like this:

    Turn off the computer.
    Turn on the computer, but while it is booting, turn off the power.
    Turn on the computer, but while it is booting, turn off the power.
    Turn on the computer, but while it is booting, turn off the power.
    Turn on the computer and wait.

After three failed reboot attempts, Windows goes into recovery mode and one of the options there is to reset the computer. One of the reasons for that option is to address this specific problem of finding an old machine that you forgot the password to, and you want to just reset the PC and start over clean.

Note that doing this requires physical access to the computer, so we're still covered by Law 3 of the Ten Immutable Laws of Security*.

Update: Clarified that this resets the PC and starts over with a fresh install of Windows, erasing any data that had been on the PC. This is not a password reset.

*The 10 Immutable Laws
Law #1: If a bad guy can persuade you to run his program on your computer, it's not solely your computer anymore.
Law #2: If a bad guy can alter the operating system on your computer, it's not your computer anymore.
Law #3: If a bad guy has unrestricted physical access to your computer, it's not your computer anymore.
Law #4: If you allow a bad guy to run active content in your website, it's not your website any more.
Law #5: Weak passwords trump strong security.
Law #6: A computer is only as secure as the administrator is trustworthy.
Law #7: Encrypted data is only as secure as its decryption key.
Law #8: An out-of-date antimalware scanner is only marginally better than no scanner at all.
Law #9: Absolute anonymity isn't practically achievable, online or offline.
Law #10: Technology is not a panacea.

More here https://technet.microsoft.com/en-us/library/hh278941.aspx

[Geek-9pm]

If you have anohter PC tahat is working, there are many wyas to reset the password of a forgotten computer. Just search for "'reset Windows pasword."

Havngsaid that, the method you describe is rather novel. 
 

[Salmon Trout]

the method you describe is rather novel. 

It applies to Windows 8 and later, I should have made clear.

[Allan]

Good post ST