Copying files failed. An unknown error occurred (-50)

I currently have a PC (Samsung Q330 running Windows 7) and I am getting a Macbook Pro in a few days! Therefore I am transferring my iTunes (10.6) library to an external hardrive (Hitachi X250). While I was doing this I received an error message that read “Copying files failed. An unknown error occurred (-50)”. Therefore I was wondering, how the heck do I fix this???

What I have done.

• I have gone in to “Advance Preferences”.
• I have changed the “iTunes Media folder location” to my external hardrive.
• I have the following two option selected “Keep iTunes Media folder organized” and “Copy files to iTunes Media folder when adding to library”.
• Then I go to File> Library> Organize Library. Then I select “Consolidate files” then I press the “OK” button.
• Then about half way in or so I get a pop up that reads “Copying files failed. An unknown error has occurred (-50).

As you can see iTunes is not working. Could anyone help me???

Thanks in advance, Donald Louch!