Is this a program you've written... it seems that that date is the 'first acceptable date' for the Windows OS (later versions, at least).
Is it possible that you are leavibg the field empty?

good luck

>As a backup I have a Batch file that ZIPs files from various directories to a CD disk.
>
>Lately, I am not sure if it is always though, after the backup is done, all ZIP file on the CD show the date of 01/01/1601.
>
>Does anyone know if this is some kind of virus or whatever?
>
>Thank you.