Failed Logon Event 675 for user Administrator

Recently setup ADAudit plus and there are thousands of failed Administrator logins. Because we have a mix of 2003 and 2008 domain controllers my searching shows there is a difference in encryption for the two but I thought adding  to 2003 would take care of those errors, doesn't look like it. I need to clean up this white noise in case there is something serious happens. I came across this and some other support topics that might be related to my problem but I want to check with experts to see if that is really the case and what do I need to do to fix it. It is documented here as well but I'm confused on the Right-click DOMAIN\EXC$ and click Properties. part not sure what DOMAIN\EXC$ means

The event error
Pre-authentication failed:
       User Name:      Administrator
       User ID:            DOMAIN\administrator
       Service Name:      krbtgt/domain
       Pre-Authentication Type:      0x0
       Failure Code:      0x19
       Client Address:

For more information, see Help and Support Center at
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

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.

Pre-Authentication is a Kerberos security feature but you can disable it on a per account basis. That will make the events go away but the root cause is probably based on the different DC version and the supported authentication methods.

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
stlhostAuthor Commented:
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
Windows Server 2003

From novice to tech pro — start learning today.