Windows XP. It is easy and it does not reset the password. Hack into a computer running Windows XP without changing the password and find out all and any passwords on the machine (including admin accounts). You do not need access to any accounts to do this. Of course, do not do this on anyone elses computer without proper authorisation.
Bypass Windows Login screen

Steps to Hack into a Windows XP Computer without changing password:
1. Get physical access to the machine. Remember that it must have a CD or DVD drive.
2. Download DreamPackPL HERE.
3. Unzip the downloaded dpl.zip and you’ll get dpl.ISO.
4. Use any burning program that can burn ISO images.
5. After you have the disk, boot from the CD or DVD drive. You will see Windows 2000 Setup and it will load some files.
6. Press “R” to install DreamPackPL.
7. Press “C” to install DreamPackPL by using the recovery console.
8. Select the Windows installation that is currently on the computer (Normally is “1″ if you only have one Windows installed)
9. Backup your original sfcfiles.dll by typing:
“ren C:\Windows\System32\sfcfiles.dll sfcfiles.lld” (without quotes)
10. Copy the hacked file from CD to system32 folder. Type:
“copy D:\i386\pinball.ex_ C:\Windows\System32\sfcfiles.dll” (without quotes and assuming your CD drive is D:)
11. Type “exit”, take out disk and reboot.
12. In the password field, type “dreamon” (without quotes) and DreamPack menu will appear.
13. Click the top graphic on the DreamPack menu and you will get a menu popup.

Hack Windows Login Dreamon

14. Go to commands and enable the options and enable the god command.

Bypass and hack user account passwords

15. Type “god” in the password field to get in Windows.

You can also go to Passwords and select “Logon with wrong password and hash”. This option allows you to login with ANY password.

Note: I was unable to bring up the DreamPackPL for the first time because I have Kaspersky Anti-Virus already running in background. I believe most antivirus already labelled this tool as a Hack-Tool. A Hack-Tool is NOT a virus. DreamPackPL helps you bypass the Windows Login screen and it is not destructive.