DCOM 10004 error after admin pwd change

We have a Windows NT 4.0 SP6a server running Exchange 5.5 SP4.

The Event Viewer in that gets me System Log errors always with the following details –

EventID: 10004
Description: DCOM got error “Logon failure: unknown user name or bad password. ” and was unable to logon Domain\Administrator in order to run the server: {179894D5-B853-4F32-A7C1-7B2E7F69D271}.

How do I resolve this? I’ve already cheched DConcnfg

Akash