I think slack is the space left over in a cluster unused.
When you go to the properties of a file, there will be "space used"
and "space on disk". Because computer hard disk's clusters are each
2048b in size, and normally they assign space to files by clusters,
so if the file is 2000b in size it gets 1 cluster, and 48b will be
left over. That is slack.
I don't use Norton, it is a bloated pile ot steaming
sheeeeet.
