HOW DO I FIX THIS PROBLEM?????

I had the same problem with mine. I messed around with it, and now it's working again. Here's what i did. Try this, and let me know if anything happens: Take out the battery. Plug the mp3 player into your computer, without the battery. Find the MP3 player under "My Computer." Right-click it, and click "Format" After formatting, leave it plugged in for a while. Add a song to it, then unplug it, and turn it on. Hopefully, the song will show up. Hope it works! -Yockub

I turn on my Sansa 230 and it just starts playing 'Unknown'. No buttons work - it just keeps the same screen until I pull out the battery
I've tried the suggestion for deleting files - Windows says that the device is write protected.
I've tried the suggestion for reseting the Sansa holding the power button on for 10 sec. - nothing
I've tried formating from Windows (right mouse click on Sansa) but format is not an option on the menu (it is for other devices)
Any ideas?

Thank you sooooooo much for this solution!!!

Delete all files of it from the computer

Yockub, I deleted all my songs with a Mac computer and I could no longer load songs. I used your trick to reformat on a PC and it worked perfectly, Thanks so much for posting your solution.

Thank's for the help..it works for me like a charm.