windows 7 - Unable to change password - Access is denied

I installed Windows 7 on a computer in a workgroup a few weeks ago. Yesterday while logging, the user (administrator account) was prompted to change its password Your password has expired and must be changed.
It is not possible to change the password, the error is Access is denied.

There is a second administrator account on the computer, but it is hidden on the welcome screen. Normally, by clicking Ctrl-Alt-Del it should be possible to log in using that account, but for some reason, Ctrl-Alt-Del does not have any effect.

I could boot the PC on a CD and reset the password that way, but the computer is situated in a secondary office a two hours drive away.

Is there something else I could do ?

Answer

Thanks to @Nikolay's link, I was able to solve the problem :

1. Boot into Bios


2. Change the system date to a day before the event


3. Log into Windows


4. Correct the problem

In the user account settings, I had checked Password never expires and User cannot change password. I was sure there would not be problems. I did not know that the computer's Password Policy - Maximum password age overrides the local user's settings in a Workgroup environment.

To change this Policy, type secpol.msc at the command prompt, and set Account Policies - Password Policy - Maximum password age to 0.