I'm receiving errors from DCs in my domain, which state that the target Principal Name is incorrect or that access is denied when I attempt to replicate AD data or to perform some domain-modification functions. What's going on?

Log on to the DC that's having the problems.

Ensure that the Windows Support Tools are installed (We'll be using the Netdom tool, which is part of the support tools.)

Start the Microsoft Management Console (MMC) Computer Management snap-in (Start, Programs, Administrative Tools, Computer Management).

Scroll down to the "Services and Applications" section and select the Services subleaf.

Double-click the Kerberos Key Distribution Center (KDC) service.

Set its startup type to Disabled and click OK.

Reboot the DC.

When the DC restarts, open a command prompt and run this command:

netdom resetpwd /server:   /userd: /passwordd: 

You should see a confirmation message stating that the machine account has been reset.

Restart the Computer Management snap-in.

Scroll down to the "Services and Applications" section and select the Services subleaf.

Double-click the KDC service.

Set its startup type to Automatic and click OK.

Reboot the DC.