Who changed my admin password?

Two days ago we found on one of my clients networks, that the Domain administrator password had been changed.    After reviewing who knows the admin password (very few people) and asking them if they may have logged in and inadvertently changed it, we've come to a dead end.    We'd like to find out HOW we can determine when and from where it was changed.   We know, from our security logs, about when it occurred, due to authentication failures coming from our barracuda spam firewall, but we need more info.  

Is anyone familliar with software or utilites that might allow us to find out how this happenned, and from what workstation or source?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Brian PiercePhotographerCommented:
If you had got auditing of privilaged use enabled then you may see it in the security log - if not - you can't
new435Author Commented:
How about some of the 3rd party utilities out there?   Isn't there something that can go into AD and look at password change history?
Brian PiercePhotographerCommented:
Too late - if they were installed PRIOR to this they might have a chance but the information cannot be recovered retrospectively.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Forced accept.

EE Admin
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
OS Security

From novice to tech pro — start learning today.