How do I get rid of the ! Mark on some of my songs in itunes?

I have downloaded a lot of songs from iTunes, and the list of songs I really want but can't find on iTunes, just keeps growing. I'm pretty sure the songs are available somewhere on the internet, but some are not actually on albums, and so I can't find them in the library either. I know about...

How do you copy songs from the radio on itunes to the windows media player?

Hello, I'm not sure where this question would best fit, but I really need help! So I had all of my music on itunes and my computer crashed. I recently got a new computer and installed Itunes, and the library is obviously empty. How can I take the music from my ipod and put it back into itunes?...