when i copied mp3's to my dad's harddrive (connected on my pc) i got this window popping up (this was quite some time ago). then about 5minutes ago i copied "format.exe" to a stiffy for a machine i want to install "virus98" on (i've got an old game that doesn't work on XP or 2000). when i clicked "paste" this sodding message popped up again. is there something i'm missing here?

I'm pretty sure that just means that the file had something attached to it thats extra but the computer can't support it. But just in case download HJT and run it. Post the log back here. (don't fix anything yet)

The message is perfectly normal- it is indicating that the files in question have metadata stored in Alternate Data Streams (ADS). The NTFS filesystem supports ADS, but they will be lost/stripped when transferred to media formatted with another filesystem (the files themselves will remain intact, however).

Nevermind then with that HJT log.

Yeah, it's (thankfully) not a malicious thing.

There's an obvious contradiction. If the file is stripped of some extra information, then the phrase that states that "the file itself will not be affected" is simply B.S. When I COPY a file from one mediom to another, regardless of the file system (I couldn't care less which one is which), I want it copied complete, up to the last bit of the last byte. If a single bit is wrong in the copy, that is, it difffers from the original, then the file WAS "affected" and the copy is worthless, as it is NOT a copy. Someone has a definitive answer, please?

It sounds as though you may be unfamiliar with the relationship between files and the filesystems on which they are created.

In your scenario, although technically it certainly is altered from the original, the copy of the file made under such circumstances is hardly "worthless"; the substantive data in the file (the data with which users and applications are usually concerned) is still intact.

Take, for example, a Word document created on a Windows machine whose hard drive is formatted with the NTFS filesystem. This Word file can obviously be copied via floppy, CD, etc. to a Mac computer using the HFS+ filesystem and opened/edited/saved/printed/etc. in that Mac's version of Word.
From the user's perspective, the file is a perfectly usable copy of the .doc file created on the PC, right?

During such a transfer though, certain filesystem-specific metadata (like NTFS permissions, for example) will get discarded, as the target HFS filesystem has no need (and often no understanding) of that metadata. Just as a point of interest, note that certain Mac-specific metadata will actually get added to the file once it is living on the Mac's HFS drive, as a Mac file is usually comprised of two forks (the Mac equivalent of Alternate Data Streams): a data fork, and a resource fork.

These "translation" issues are just the (mostly) unavoidable effects of transporting/transferring files between disparate filesystems, given that metadata (such as Alternate Data Streams, Forks, Extended Attributes, Permissions, etc). are usually specific to the filesystem under which a file was originally created. If you need a true/fully-intact copy of a file, you will need to maintain filesystem consistency across the media on which the file is transferred.

A nice read, DMR. Thanks.

Gee, DMR, thank you for your VERY educated answer, and for shedding light on the subject. Now I fully grasp what that messsage and these comments were talking about. Thanks again!

Glad I could help