After months and years of backing up certain things... you may have created Test Sets and just no longer needed certain created Sets due to servers no longer being online or backed up... and you end up with lots of old sets you no longer need... to clean this up as a maintenance (trimming the hedges), you can do the following:
There are two ways to do this... Unfortunately both are time consuming:
1. Stop Netvault Services, browse your way into the netvault "db" directory and rename your "ScheduleDatabase" to "Old_ScheduleDatabase"... but, the downside to that would be you'd have to re-create all your backups once more (restoring the Schedule Manager/Database from your last NetVault Database Backup would only bring everything back).
~OR~
2. Go into your Backup Window (as if you were going to create a backup), click on "Load" (to load one of your backup sets, that you want to delete), once loaded you'll click on the "Modify" box and then Modify button (from the pop up). Once you've done that the "Delete" Button at the bottom will become available, click on that and it will "Delete the Backup Set" you loaded and were trying to get rid of.
You will have to do this for each and every one of the Backup Sets, individually, that you want to get rid of.... and this whole process can be used for each of the other tabs you have "sets" for as well, to get rid of them and clean things up. To prevent having to do this for 100's of jobs in the future... I would suggest cleaning up these sets every few months... as a maintence, to keep things nice and clean and of course so you'll only see sets you're actually using and don't mix things up with Duplicates.
