Helping people with computers... one answer at a time.

Getting into that old computer is probably not a good idea. Better to start from scratch.

I recently got a second-hand PC, which I can't access as it's asking for the previous owner's passwords. I've tried reinstalling Vista, but I can't get past the login screen. I can't get a Start menu. Thank you.

In this excerpt from Answercast #19, I look at a second-hand computer that is protected by the previous user's password and give my strong recommendation on how to proceed.

Accessing a second-hand computer

When you get a second-hand PC, you are getting whatever's on the hard drive. That could be an installation of Windows.

  • What you don't know about that installation of Windows is if it's riddled with malware or spyware!

So, what I'm leading up to is the fact that you can't login, the fact that you don't have the previous owner's password means nothing. Even if you did, you should not login!

You are putting yourself at the mercy of whatever it is they happened to install on that machine prior to your ever having laid hands on it.

Format that drive!

My strong, strong, strong recommendation is that you format the hard disk.

Use a utility like DBan to completely erase everything on that hard drive and reinstall from scratch.

How to reinstall

  • You've indicated that you've tried reinstalling, but you can't get past the login screen.

Unfortunately, that tells me that you're probably not reinstalling correctly. When you install an operating system, there is no login screen as part of the installation process. You grab the original media, the CD or the DVD (for Vista, in this case) and you boot from it.

Once you boot from it, it then walks you through the operation of reformatting the hard disk:

  • Installing the operating system from scratch.
  • Setting up user accounts.
  • Setting up Windows.

You would then login using the user account that you originally set up as part of this setup process.

Do a thorough reinstall

So the short answer is don't trust what's on that hard drive! It's just not worth it. Reformat it. Reinstall Windows and you should be fine.

That's the best to way to actually use a second-hand machine.

Article C5368 - May 21, 2012 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

May 22, 2012 9:23 AM

Don't know if it's still the case, but some PCs came password protected at the initial boot, way before the Windows password kicked in. I read that there is a jumper on the motherboard that can be removed to reset that password. Probably need a map of the motherboard, if it isn't labeled, which some were.

May 22, 2012 9:27 AM

You may be able to download a program from nirsoft dot net to create a boot disk to allow you to reset the password...

Robert R
May 22, 2012 10:36 AM

Could be a power-on password. If so, and you can get a copy of the hardware maintenance manual (easy for Lenovo, they're all on the web), it will usually show you how to reset the power-on password.

May 22, 2012 1:21 PM

Can you boot into safe mode?

John Servis
May 22, 2012 7:16 PM

It depends on what type of password it is requesting. If you're not getting past the Bios screen and seeing any sign of Windows start-up, the Bios is password protected and just as Robert R. stated above, the Bios has to be reset.
If this is a desktop pc it's not a real big issue, just Google how to reset the Bios/Cmos on your make/model machine. If we're talking about a laptop, well, you might be screwed. It depends on the make/model and age of the laptop.
If you're seeing any windows logo at start-up, just follow Leo's answer and all will be well. Good luck. J.

May 24, 2012 5:50 AM

I'd recommend Hirens (now at version 15.1 I think). It contains dozens of tools, including Offline NT Password Changer 2011-05-11. If the Linux command prompt interface for this tool is a bit too daunting, I'd suggest Ophcrack Vista. It has a much more user friendly interface, and is extremely effective. You can also download Ophcrack XP, and keep it for future use.

May 24, 2012 3:02 PM

You may have to remove the CR2032 battery to clear the BIOS power on password. Everything should auto detect and you will be just fine. It may take 5 to 10 minutes for the memory to clear, along with the power on password. No manual needed. The jumper applies to the flash memory, only.

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