How to identify an original file from copies

[dilettante]

Out of interest do any of the alternate textstream properties stay with files that are transferred to FAT drives, or do they always fall off this way?

FAT filesystems have no alternate data streams.

Problem is the FAT format again, as soon as you try and move the original to a FAT drive the achive attribute is set to on automatically.

I thought you wanted to detect copying. That would be copying.

Another thing in relation to anti-piracy, are comments included in the compiled exe or are they discarded by the compiler?

No, comments don't get copied into the compiled program, but many symbolic names do (Forms, Classes, Methods, Properties, etc.).