How to Enable and Activate Administrator Account in Vista and then Unhide or Show in Welcome Screen

To activate the administrator account in Vista, follow these guide’s instructions:
Logon to Windows Vista with normal user account username and password (must belongs to Administrators group).

Click on Vista Start button, and type cmd in the Start Search box.

Right click on the Cmd returned on the search results pane above, then select
Run As Administrator

In the Command Prompt window, type the following text at the command line to set a password for administrator account. If you want to use a blank password for the Administrator account, skip this step.

net user administrator password

Replace password with the actual password string that you have chosen. Press Enter when done.Note that if your computer is a member of domain controller or has enabled complex password requirement in Local Security Policy, you will have to pick a really hard to remember password mixed with symbols.
Next type the following command and press Enter to activate and enable Administrator account:
net user administrator /active:yes

The process should completed with the following message:
The command completed successfully
If not success message is returned, repeat the process again.
Logout from Vista by choosing Log Off or Switch User.

Click on Administrator icon and logon with the password you selected

to disable Administrator account
type

net user administrator /active:no


If you’re not comfortable in using command prompt in activating administrator account in Windows Vista, there is another easy way to enable the Administrator account by using graphical user interface (GUI) within Vista desktop.

Click on Vista Start button, then go to Control Panel.

Inside Control Panel, click on System and Maintenance link, follow by Administrator Tools at the bottom.

An Administrator Tools window appears.

From there, click on Local Security Policy applet.

Alternatively, type secpol.msc in Start Search box and press Enter.

Click Continue on User Account Control’s Windows needs your permission to continue running Microsoft Management Console (MMC) dialog box

On the left pane of Local Security Policy MMC, expand Security Settings (should be opened by default), then expand Local Policies.

Click on security options baranch

Double click on Accounts: Administrator account status setting, then select Enabled radio button on Local Security Setting tab of Properties window.
Click on OK button.
Log off, switch user of restart your computer to logon with activated Administrator account.