Windows 7 password rejected after motherboard replacement

Question

I just replaced the motherboard of my HP desktop (with the exact same model). Problem is, Windows 7 doesn't accept my previous passwords (admin, user). I then used a bootable DVD for password revovery: for the admin password, it says 'empty'; for the user, it found the correct password. But this password isn't accepted anyway by Windows 7. So I'm stacked: what should I do? Thanks in advance for any help / advise !

Answer 1

Kon-boot will do the trick. Try the free version:

http://piotrbania.com/all/kon-boot/index2.html#free

Kon-Boot is an application which will silently bypass the authentication process of Windows based operating systems (both 32-bit and 64-bit). Kon-Boot modifies the system kernel while it boots, changes are made temporary only. Rebooting the machine will restore the original contents of Windows kernel and its corresponding authentication procedures.

Answer 2

Boot from a System Repair disc or a regular Windows 7 install disc, choose repair your computer when WinRE loads then use the command prompt utility to reset the password for any account you have. You can also boot from a System Repair disc or a regular Windows 7 install disc to load Recovery Environment.

Once you are at the command prompt type the following commands one at a time and hit enter key, be sure to include spaces. (Note on some HP PC's the OS partition may be mounted as D: in WinRE, so if you get errors using the C:\ command try D:.

copy c:\windows\system32\sethc.exe c:\

copy c:\windows\system32\cmd.exe c:\windows\system32\sethc.exe

when prompted to Overwrite, Type : Yes and hit Enter key again, close the command window, and restart your PC.

When you reach the LogOn screen hit the Shift key 5 times, a command window will open, Type the following, include spaces:

net user (type the name of the account) (Type any password)

hit Enter Key, and when prompted to overwrite, Type Yes, and hit Enter Key again, and close the command window, and log on with the new password you just created.

After that you might want to put the original sticky key file back in its place, so go ahead and boot your PC with the repair CD or USB that you made early in this tutorial, and in the command prompt window type the following:

copy c:\sethc.exe c:\windows\system32\sethc.exe

press Enter, then when prompted to Overwrite, type Yes and hit Enter key again, then close the window, and restart the PC.

Source of Information

Answer 3

For things like this and more, I use Hirens Boot Disk. It's filled with all kinds of great (freeware/Shareware) software and all nicely packaged to run on one CD. I've put a link here.