I have a LaCie external hard drive that I'm using on both Windows 7 and on Mac OS X. I've noticed that when I create files on the drive while it's plugged into my Mac, when I bring it back into Windows those files have some type of hidden files associated with them.
They typically start with a period and an underscore, then have the same exact file name, such as
._filename.ext and are faded out gray so the OS doesn't recognize them.
What are these files for? Are they necessary to keep? Are they taking up extra space on my hard drive? Can I just delete them from the drive while I'm on Windows?