Snapshot files store information about the state of the computer. Essentially, snapshots are a picture of the computer at a point in time. During a policy run, Symantec ESM compares the current state of the computer to the one recorded in the snapshot. Symantec ESM then reports any changes as potential security problems.
See About the snapshots.
To update a snapshot
Expand the summary branch and select a policy run. Security messages are visible in the grid.
Select the required messages in the grid.
To select adjacent rows, drag across the row numbers, or select the first row number, and hold down shift while you select the last row.
To select non-adjacent rows, hold down Ctrl and select the required row numbers.
You can only select multiple rows using the column with the row numbers.