What can I do if I forgot my Windows password?

I got a brand new Windows 7 machine, installed the operating system, created one account and forgot its password. What can I do?

There is no external CD, the operating system is loaded from somewhere inside the machine.

I already tried to remember passwords and tried all candidates with all possible combinations of caps lock, num lock, etc.

1. If you have an Ubuntu live CD you can reset it using chntpw application
2. You can use Bart's PE + Password Renew to reset the password
3. You can use Offline NT Password Editor to reset the password.

Detailed instructions on using any of the 3 are available over here.

If you can find a Microsoft ERD 6.5 boot disk, it can reset the Windows 7 password. It has to match the bit version to work, 32 or 64-bit Windows 7.

ERD comes in 3 versions

5.0 for XP

6.0 for Vista

6.5 for Windows 7

There is an alternate method for Windows 7, all you need is either a Windows 7 install disk, System Repair Disk or WinRE partition on the hard drive.

Use F8 or boot from the disc, once RE loads choose repair your computer, then load Command prompt and run these 2 commands, the second command you will get a prompt to overwrite, say yes.

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

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

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

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

and 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 used earlier, and in the command prompt window type the following ( see picture below ):

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.

Run an Ophcrack LiveCD to try and crack the password, provided that you have a sufficiently easy alphanumerical password.

Offline NT Password Editor

Offine NT Password & Registry Editor works basically the same as PC Login Now in that it erases your Windows password instead of recovering it. You can then simply log in to your account without entering a password.

source

Grab a copy of unetbootin from here. Install NTpasswd onto a flash drive. By running NTpasswd off the flash drive you'll be able to reset the password on the computer to blank. It's pretty easy to use as well.

You can gain command line access (in SYSTEM context) to a Windows computer by changing a couple of registry values. You can then reset passwords, create new accounts, run cracking tools, and so on.

This is the short version, for advanced users and sysadmins:

1) Boot to Windows 7 from the installation or repair DVD, or from Windows PE 3 boot media, or from a Windows 7 installation on another HDD. (If the target OS is Vista, use the Vista installation DVD, or Windows PE 2, or another Vista installation. If the target OS is Windows XP, use Windows PE or another Windows XP installation.)

2) Load the SYSTEM registry hive from the target OS. Back it up first.

3) In the Setup key, change SetupType to 2 and CmdLine to cmd.exe.

4) Boot the target OS. You’ll get a command-line window in system context.

There are more details here including instructions for non-experts on using this technique to reset a password. (Remember that resetting a password will result in the loss of all encrypted files and data.)

You may use Emergency Boot CD to reset it:

http://www.prime-expert.com/ebcd/

Use konboot to boot into the system bypassing the login. After you login change to your required password.