Help! Exchange MTA wont start-Error 2140

NT Server 4.0 SP6A. Exchange 5.5 SP4. – All of a sudden this morning my MTA service won’t start, nor will the IMS – because of the MTA. in the event log I see a Service Control Manager error:

The Microsoft Exchange Internet Mail Service service depends on the Microsoft Exchange Message Transfer Agent service which failed to start because of the following error:

The operation completed successfully.

If I try to manually start the MTA I see:

Could not start the Microsoft Exchange Message Transfer Agent service on \\Server Name
Error 2140: An internal Windows NT error occurred.

Never seen these before. Researched the errors already to some extent. Checked password on services. OK. Checked disk space. OK. All other Exchange & Exchange related services are running fine. Don’t understand why suddenly the MTA won’t run.

Any ideas???