Why can I not delete tracks/album from the hard drive?

Plug into computer via USB, select SYNC option, You can select individual songs or albums for deletion. Simply right click on the song or album to be deleted and scroll down to the "Delete" option. Confirm to delete from library. Once unplugged it should let you know that the library was updated and go to the main screen. You can then just go through same process as you did the first time to add new music. Hope this helps. Should be a quick process.

Yeah, It will stop syncing them and delete them from the phone

Connect the Sansa to your computer using the supplied cable. Open up an explorer window. You'll see your Sansa either as a removable hard drive or as a Sansa, depending on the USB mode. Either way, navigate into it, then into the MUSIC folder. You can delete entire albums from here, or navigate into the albums and delete individual tracks.

was your action deleting or just removing ?

>
Removing Tracks On your player, to remove tracks is to remove them from the Selected Music view only. The tracks are still in the player and can be accessed from submenus like Artists or Albums.
x! To permanently remove tracks, use the delete function. See Deleting Tracks. x!
On the main menu, select Music > Now Playing.
Press OK. In the Now Playing view, the progress bar changes to a rating bar.
Press OK again. The Selected Music view appears.
Press or to select a track.
Press and select one of the following:
Remove > Remove Track
Removes the current track from the list.
Remove > Remove All
Clears the list.
<
x!
Deleting TracksThis action permanently deletes tracks from your player.
> To only remove tracks from the Selected Music view, see Removing Tracks. <

On the main menu, select Music.
Select any submenu with audio tracks, for example, All Tracks.
Press or to select a track.
Press and select Delete Track
x!
(details from "view all knowledgebase solutions" on the site of Creative)
http://support.creative.com/Products/ProductDetails.aspx?catID=213&CatName=MP3+Players&subCatID=214&subCatName=ZEN&prodID=17897&prodName=ZEN+Mozaic

This solution only applies to the SA178:

1. Select the track that you would like to delete in play mode.
   
2. Briefly press the MENU button.
   
3. Select DELETE, press to confirm your selection and press again to confirm delete. The message DELETED! will show on display.

If you go into Windows Media Player, you have to change the Library option from Music to Photos and THEN go into the Sync tab - should now display photos instead of music.

Alternatively, you can double-click My Computer, double-click the icon of the Sansa, and find the images or picture folder - you may have to change your usb mode to msc in order to view this folder (don't forget to change it back later, or not all of your files will show up when you want them to). ONLY delete image files - if you delete system files, your mp3 player will become unusable.

Or, you can follow the method reccomended by your manual - the full user's manual is available from Sanidsk's website:
Delete Photos and Video
The photos are stored in 2 locations on your Sansa…My Album and
Thumbnails. The instructions below for deleting photos and video from your
player were created using Windows XP with Windows Media Player 11.
To delete photos from your Sansa, please execute the following steps:
1) Connect your Sansa e200 to your computer
2) Select Open device to view files using Windows Explorer on initial
connection
3) Click the drive containing your photos
4) Click on the photo folder.
5) Highlight and delete the photos stored in My Computer\Sansa
e200\...\Photo\My Album and My Computer\Sansa
e200\...\Photo\thumbnail\My Album.

To delete a Track from a playlist, you must currently have that Track selected in the display. Pressing the DEL TRACK button will cause a confirm delete page to be displayed,where "Song 01" is the name of the Track to be deleted. Pressing UP/YES will remove that Track from the playlist, moving the next Track in the playlist in its place. Pressing DOWN/NO will cancel the operation and return the unit to its previous state.

NOTE: Deleting a Track from a playlist does not delete the audio samples from the hard disk. The audio remains on the disk in an "Audio File"

if same as am-f70 press play then rec/edit with red button pressed, advance mode button till erase is displayed (trk only) or erase all (whole disk) hope this helps!

You should try taking the battery out. if you unscrew the for screws on the back there will be a battery just take that out and put it back in this should delete everything if it doesnt then i dont know. dont worry about takeing it apart your only takeing the back off to where the battery is. just like your cell phone.

I had the same problem, but only for one album's tracks. I've fixed it by connecting the player to my PC, opening Windows Explorer, then deleting the songs listed under the Artist and Album folders, and then I found a separate entry for each individual song and deleted those too. Maybe I'd accidentally added the album twice at some stage.