By default the “Administrator” account is disabled in Windows 7.
It can be enabled and used however some caution should be used- when logged on as the Administrator account the UAC system is disabled which potentially allows malware to install in the background.
To enable the Administrator account:
- Click on the Windows (Start) button
 - Right click on ‘My Computer’
 - Select ‘Manage’
 - Expand ‘Local Users and Groups’
 - Select ‘Users’
 - Double click on “Administrator”
 - Un-tick ‘Account is disabled’
 - Click ‘OK’ to save the changes
 - Right click on “Administrator”
 - Choose ‘Set Password…’ , click on ‘Preceed’ and give the account a new password
 - You will now be able to log in using the Administrator account.