My computer recently crashed, and whern I tried to restore my files onto a new computer most of them were there, but there were a couple files that just didn't show up. I never got an error message when Norton was running a backup, which I had scheduled to run while the computer was idle. Why did these files not backup, and why did the program not inform me that the files couldn't be backed up?
The files were project files for Ableton Live, which is an audio recording program. As far as I know, these are the only files that didn't restore.
Norton 360 Backup works based on categories. When you go to the "What" tab of Backup, you can select "Pictures", "Music", "Financial Files", etc. I am assuming that you already know this and that you at least had the "Music" category checked. The way N360 chooses what category a file falls under is by checking the file extension (.exe, .jpg, .avi, etc.) of the file. So, vacationPic.jpg is backed up if you check the "Pictures" category and funnyVideo.avi is backed up if you check the "Video" category. If you check the "Edit file types" check box and then click configure on the "Music" line, a box will appear that shows you what file extensions fall under the music category by default. I have not used Ableton Live, but the internet tells me that the file extension for Ableton Live project files in .als. Unfortunately, you can see that this extension is not included as one of the default extensions under the music category, so that means those files would not be backed up by default.
If you ever want to see a list of what files are being backed up, you can click the "Preview" button in Backup. If you want to add Ableton Live project files to be backed up in the future, there is a "Add New" button in the file extension dialog box that will allow you to add custom extensions like .als.
For your current files, depending on how important they are to you, there are services that can get information off of almost any crashed drive. They tend to be pricey though.
Best of luck, and I hope this helps explain your question.