Why are there "Bad Tracks?"

have you consulted customer service on this? It sounds to me like it might be a drm issue, where drm is a form of licensing that stop you playing files without the license.If it is that kind of problem Sansa should recognise it straight away and then you'll know what to do. in the meantime you could try doing a reset as per the instructions that came with the player or go to the website and download the manual.

Change the connectivity to MSC mode. Settings->USB mode->MSC. Now connect it to your PC and remove the tracks if any. Reply if you need more assistance

Your DB might be corrupt. Folow the delete procedure one more time:
Delete Music Files
1) Connect your Sansa to the computer.
2) Select Open device to view files using Windows Explorer on initial
connection.
3) Select the place where you want to delete music files from
4) Highlight and delete the music file/s or folder from My Computer\Sansa
e200\...\MUSIC folder. (You can also select from a variety of music
software programs to transfer/synchronize your files).

If that fails, go ahead and update the firmware - it will delete everything, and allow you to start over from scratch among other things.

-Tha Mp3 Doctor

For the bad tracks go Under Settings, look for Mode or USB Mode. Put the unit in MSC (if that's available) or Rhapsody.

Connect it to the computer. See what driveletter it is :F: Sansa E280...G: Sansa E280... whatever it is.

Click Start/Run and type in chkdsk F:/f (or G: or whatever the letter is) . That will check and may fix the bad files.

I hope that helps
Please rate accordiingly
Thank you
Computerrep

The songs are in the wrong format or have expired licenses

There are 2 ways to format an mp3 player - if you were formatting the mp3 player from "My Computer," then try reformatting from Windows Media Player instead - I have a "tips and tricks" entry on How to Format an Mp3 Player for details

If that doesn't work, then double-click on My Computer, double-click on the Sansa player, and go to the various folders that it lists - music, voice, etc. Delete the songs ONLY - do not delete the dat, bat, ini, inf, or other system files

Two possible methods:
Go ahead and do this, in case the DB is corrupted:
Format - Erases Everything: Connect your Sansa player to the computer and open Windows Media Player. Click on the Sync tab. Pull down the drop down menu underneath the Sync tab by moving your cursor over the Sync tab and left clicking on the little black arrow underneath the Sync tab. Highlight "Sansa 1GB" (wording may vary slightly), and then select "Format." - this should erase everything.
Firmware Upgrade- Erases Everything: Get the latest firmware upgrade from Sansa - it updates the firmware and erases every song in the player all at once. Note: this method doesn't work if already have the latest firmware. Go to this website and click "Firmware Updater" to find out: http://www.sandisk.com/Retail/DriverDownloads.aspx

same thing happened to me it still doesn't work and mine is supposed to hold 500 it only holds 150

Isn't it that you just go to my computer and delete it there?
It says to delete it entirely from it.

Well To Get It To Power Off You Just Hold Down The Power Button For Like 15 seconds. That Does The Trick. But As For The Unknown Artist Bit...I Dont Have A Clue!

Try this: disconnect the player from the computer, hold in the volume + button, and reconnect the player to the computer while holding the volume + button in. Keep holding the volume + button for an additional 5-50 seconds. Windows should eventually go into recovery mode and revive the player- it will pop up a window that says Found New Hardware Wizard.
-----
Download the Sansa Recovery Tool from the Sansa website.
Format - Erases Everything: Connect your Sansa player to the computer and open Windows Media Player. Click on the Sync tab. Pull down the drop down menu underneath the Sync tab by moving your cursor over the Sync tab and left clicking on the little black arrow underneath the Sync tab. Highlight "Sansa 1GB" (wording may vary slightly), and then select "Format." - this should erase everything.
Firmware Upgrade- Erases Everything: Get the latest firmware upgrade from Sansa - it updates the firmware and erases every song in the player all at once. Note: this method doesn't work if already have the latest firmware. Go to this website and click "Firmware Updater" to find out: http://www.sandisk.com/Retail/DriverDownloads.aspx
or
http://www.sandisk.com/DriverDownload/driverList.asp
-Tha Mp3 Doctor