I want to share - really
 

I really want to share, but even though I set up, on installation, an HDD full of stuff, I'm only sharing 11 files and all the folders are all marked red (which I think means it's not being shared). I then right-clicked on the all the folders individually and clicked on "share". Some of them turned to black, some of them stayed red, but all were back to red after a system restart. Is it me or what?

What type of files are they(mp3, avi, exe)?

can't really see what difference it makes, but they're a fairly even mixture of all of those, plus jpegs

By default some file types aren't shared, but that doesn't appear to be the problem.