How I can restore the administrator user account?
When I was able to create a password to the computer, I have wrongly created a new user account in my name. After that the computer displays only the new user account that I have created wrongly. The original user account that is administrator was disappeared. How I can view the administrator user account which contains important files? The new user account that I have created wrongly does not contains any files that I have saved.
Once you have created regular user accounts, the default Administrator account vanishes from the Welcome screen (what you see when the computer starts up). Press Ctrl-Alt-Delete twice at the Welcome screen to retrieve the standard logon dialog. You can log on as Administrator from here. To switch among accounts, just click the Log Off button on the Start menu. You'll then see the Log Off Windows dialog box. Click the Switch User button, and you'll be taken to the Welcome screen where you can select and log on to other accounts.
There is a tweak program that you can use to force the Administrator Account to show on the Welcome Screen.
Another is at http://www.winguides.com/registry/display.php/1165/
Of course Microsoft's own TweakUI will do the trick too with a simple check in the "Show Administrator on Welcome Screen"
And since all these tweak applets are just editing the registry, you could do it yourself as follows:
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList
Add the DWORD value 'Administrator' with a value of '1'
You are done.