I recently upgraded fropm Exchange 2003 to Exchange 2007 and from BackupExec 10 to BackupExec 11 (for only version 11 has support for exchange2007). Since then I try to backup my exchange, but it doesn't work as expected. I have scheduled a full backup once a week and a differential backup all the other days. The full backup works as expected, but when I am running the differential backup I always get the error Incremental and differential backups are not possible, because one or more of the Microsoft Exchange transaction log files has been deleted since the last backup.The store that can't be backed up differntially is a public folder store that is replicated from a 2003 source. I can't find any location to specify that exchange 2007 shall keep its transaction log files... Help appreciated Guenter

Check the transaction log settings for your storage groups. Make sure circular logging is disabled. If circular logging is enabled, then log files are automatically deleted once they're commited to thedatabaseand it is impossible to do differential or incremental exchange backups. Dan http://technet.microsoft.com/en-us/library/bb331968.aspx (how to enable/disable circular logging)