The built-in Administrator account is found on the Welcome screen only if there are no other accounts available, other than Guest, or when the computer is booted into Safe Mode.
To get Admin account on the “Welcome Screen” make sure that there are no accounts logged in.
The built-in Administrator account can create and change passwords for all users, but cannot restore a forgotten one.
When a password is changed, that account will lose all encrypted files, personal certificates and stored Internet Explorer passwords or network resources.
Press “CTRL-ALT-DEL” twice to get the classic Windows logon box. Type: Administrator. If this account has a password, enter it. Otherwise, leave the it blank.
Recovering a password is much more difficult. Using a cracking program can take weeks!
RESET A PASSWORD USING THE ADMINISTRATOR ACCOUNT
1. Boot into Safe Mode.
2. Log on using the built-in Administrator account.
3. Open: Control Panel -> User Accounts.
4. On the Users tab, select a user name, the password to change and click Reset Password.
RESET A PASSWORD AT THE LOGON SCREEN WITH THE COMMAND PROMPT
At the logon screen, press Shift+F10 to open a Command Prompt with administrative privileges and type:
net user {username} {password}
{username} = The Account’s User Name
{password} = This will be the new password
RESET A PASSWORD USING MICROSOFT’S ERD COMMANDER
1. Download a 30 day trial from here:
Microsoft Diagnostics and Recovery Toolset 5.0
http://www.microsoft.com/downloads/details.aspx?familyid=5D600369-0554-4595-8AB4-C34B2860E087&displaylang=en
2. Install it, run it and burn the image to a CD.
3. Boot the CD and run the Locksmith Wizard, found under Start -> System Tools.
4. The Locksmith Wizard is very easy to use, just select an account and input a new password. Too easy!