Exchange 2000 Backup

Hi,

After a do an on-line backup of the exchange 2000 server, I get a message saying
Backup started on 27/11/2008 at 01:19.
The Microsoft Exchange service on \\SYS\Microsoft Information Store\First Storage Group has
reported an error. Check the event log for more information.
Backup completed on 27/11/2008 at 02:04.
Directories: 2
Files: 2
Bytes: 15,677,276,522
Time: 45 minutes and 26 seconds

I have done the backup a few times, and always get this error. Where exactly in event viewer (or elsewhere) do I find a solution ?

Kind Regards
Kev