Hi Robin,
The Administrator account is available only in the safe Mode in Windows XP
Home Edition.
When you install Windows XP Home Edition, you are prompted to enter a
password for the Administrator account. After the installation has
completed, you can only use the Administrator account in Safe mode. When
you use the Administrator account to log on to the computer in Normal mode,
you may receive the following error message:
Unable to Log You on because of an Account Restriction
CAUSE
This issue occurs because the Administrator account has been set aside so
that it can be used in Safe mode when the Owner account is not available.
STATUS
This behavior is by design.
MORE INFORMATION
The Administrator account is not displayed in User Accounts unless the
computer is in Safe mode. To change the password for the Administrator
account:
Click Start, click Turn Off Computer, and then click Restart.
After the computer completes the Power On Self Test (POST), press F8, and
then click Safe mode.
NOTE: If you have difficulty getting to the Safe mode menu command, press
F8 repeatedly after you turn on the computer.
Log on as an Administrator, or with another account that has Administrator
permissions.
Click Start, click Settings, click Control Panel, and then click User
Accounts.
Click the Administrator icon.
Click Create a Password or Change my password.
Type a password for the account, and then retype the password to confirm
it.
Type a hint to help you remember the password in the event that you forget
it.
Click Create Password or Change Password.
or
http://support.microsoft.com/?kbid=290109
S.Vijay
This posting is provided "AS IS" with no warranties, and confers no rights