Reset it. It won't take your music or games off. Push the middle button and the top button and hold it for ten seconds. If that doesn't work then you will have to reset the whole thing.
If 1 doesn't work then plug your ipod into your computer, then open itunes. Once you have opened Itunes go to your ipod and there should be different settings (tabs above the picture of ipod.) Click on one of those and your memory will show and a bunch of other stuff, Click on something that looks like something you would use to reset the whole ipod. Then it will tell you that your ipod is reset.