hallnona, you will have to restore the iPod touch through iTunes.
1.plug your iPod touch to your PC or Mac with the USB cable.
2.hold the sleep/wake button and the menu button on the iPod at the same time.
3.Keep the buttons pressed, till you see the ‘restore’ screen on the iPod touch. The restore screen will have an iPod cable and an iTunes disc symbol. When the restore screen appears, release the buttons.
4.iTunes will display iPod touch. At the same time, there will be a message displayed, that the iPod touch is in recovery mode.
5.now click on the ‘Restore’ button in iTunes to restore iPod touch.
The bad thing about this is that all the contents of the iPod touch will be erased. Hope this helps and good luck to you.