Environment:
All computers are in workgroup, no domain, about 250 XP professional with sp3, 250 Windows 2003 Standard servers with sp2, problems are affecting about 5% of the computers, but number affected is on the increase. All the user accounts are local administrators. Local security policy does not restrict user rights (that means default settings are used), default settings for password policy and account lockout policy. All administrator accounts have the "password never expire" attribute set.
Symptoms:
Some users cannot logon, after keying the correct password, Windows issues "Access is denied" and promptly returns to the logon screen. When an unaffected account logs on, password reset the affected account, the affected account can again successfully logs on, but the problem may or may not return (sometimes just one day later problem returns).
Nothing drastic has been changed on the systems (such as installing new software, updating patches), problems occur suddenly.
re-creating user profile does not solve the problem.
Deleting and re-creating user account does not solve the problem.
There is no indication of logon failure or authentication failure in the event log.
So far, Googling has not return much useful hints.
So far affecting only Windows XP and Windows 2003 (but that is because these are the major OSes in use in the environment).
Very frustrating.
Help is appreciated.
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