Backups created with SQL Backup 7.0 and 7.6 can be restored using 6.4. The intervening versions (7.1 to 7.5) should be restore-able too. Note that this is dependent on the underlying SQL Server version. If the 7.x backup was made on a SQL 2012 instance, you still won't be able to restore it using SQL Backup 6.4 on any pre-SQL Server 2012 instance.
SQL Backup Consultant Developer
Associate, Yohz Software
- SQL Backup goodies under the hood, updated for version 7