Validate target :
Make sure that the target is actually the one you want.
For example, be sure that it is your USB Memory key that is attached and not the one of a colleague or friend.
Verify change date :
Copy source only if it is newer than target (for faster "copy all")
Preserve directory structure :
The full path of the source is maintained on the target.
if source is C:\dataVnyDocuments\and target is E: Vnybackup\ then if the file C: \dataVnyDoajmentspersonalVwofile.png changes the result will be:
* if option Preserve directory structure" is enabled then the file will be copied to E:V^ybaclajp\cVJal3VnyDocument5V)ersonalV5rofile.png
* if option Preserve directory structure" is disabled then the file will be copied to E:VnybadajpV>ersonalV>rofile.png
In case the option is enabled, be sure that the path does not become longer than
the longest path supported by your target location.