userenv error on Exch 2k server

I have Exch 2k running on a W2k server, which is one of two DC’s but it is not the root, or anything else special. DC’s are SP4 and pretty well current on Windows patches. Am having several errors I am looking into, but one I can’t figure is:
Event Type: Error
Event Source: Userenv
Event Category: None
Event ID: 1000

User: NT AUTHORITY\SYSTEM
Computer: Computername
Description:
Windows cannot determine the user or computer name. Return value (14).

Q329708 describes this problem and says This issue may occur if the computer account for the computer listed is corrupted.
It advises removing and rejoining to Domain. I don’t think I can do that on DC. ? Anyone have anything to add or suggest?
Thanks.