Verified answer

You have to reformat it in order to use the computer

Ophcrack can easily sniff out Windows passwords if it is not strong enough and can be found in the dictionary:

http://ophcrack.sourceforge.net/

You can burn it to a CD or create a bootable flash drive. The instructions are there.

If Ophcrack can't find the password, your next option is to just erase the password. One software that comes to my mind is the free Offline NT/2000/XP/Vista/7 Password and Registry Editor will do the trick:

http://pogostick.net/~pnh/ntpasswd/

There's a tutorial here if you are interested:

http://www.hirensbootcd.org/resetting-windows-pass...

You can also do it with the Sticky Keys trick. Here's how:

1. Get a Windows 7 installer disc or any bootable media that will give you access to a Command Prompt. If you don't have one, go to another Windows (Vista or 7) computer and create a System Repair disc by pressing the WinLogo+R keys and run RECDISC.

2. Set your computer's BIOS to boot from the disc. Access the Command Prompt under the Repair computer > System Recovery Options. Type the following commands:

c:

cd\windows\system32

copy sethc.exe sethc_orig.exe /y

copy cmd.exe sethc.exe /y

*Note: If you see a message saying "The system cannot find the path/file specified.", it means your Windows is in the D partition, not C so instead of typing c: above, change it to d:

3. Remove the disc and restart the computer. At the log in screen tap the Shift key repeatedly at least 5 times. When the Administrator Command Prompt appears type the following command:

net user login_name *

Example: net user "Simply RED" *

The quotation marks are necessary if there's a space in your log in name.

Just keep it blank and confirm it. If you see the message "The command completed successfully", close the Command Prompt. You should now be able to log in to the account without a password.

But before you start rejoicing, you need to undo the changes that you have made to the SETHC file. Otherwise, you will not be able to use the real Sticky Keys feature or somebody else could use that exploit to change your password or even lock you out again. This cannot be undone while inside Windows so you have to boot again from the disc, access the Command Prompt and type the following:

c:

cd\windows\system32

copy sethc_orig.exe sethc.exe /y

Again, if the path is not found, change the c: to d:

Follow the below steps,

1. Reboot your machine.

2. Press F8 before the Windows boot screen appears.

* Do not press F5 as used on the NT/9x series of Windows.

3. You will be be prompted with a boot options menu.

4. Select the Start Windows in Safe Mode option.

5. Click through several self-explanatory screens until your reach the familiar 'Welcome' screen.

6. Note that this welcome screen is limited to 256 colors and 640x480 resolution because the primary graphics will have been set to the Windows Safe Mode software VGA adapter. You will not be able to change this mode even in Display options, while Windows is running in Safe Mode.

7. Find the icon for the Administrator user. If the default settings of your system haven't been changed, there should be no password for this account.

* The Safe Mode Welcome screen might display some of the other users on your system.

8. Login as the admin.

9. Press Yes at the prompt asking if you would like to continue using Safe Mode.

10. Continue on to the User Settings control panel. Here you can change any of the other passwords for user on the machine. Make any changes you want.

11. Reboot your computer. As long as you don't press any keys (i.e. F8) during the boot-up the computer will startup normally.

12. Login as the user for which you set the password.

Nope