Accidentally disabled the only account

You can't disable the administrator account



-----Original Message-----
I have a client who has XP Pro installed on his office
computer. He downloaded some updates and started having
to click his username, which was administrator, to log
in. He didn't like it, so he disabled the administrator
account. Unfortunately it was his only account and now
he can't access his data. Is there any way to reenable
the account without logging in??
.