Audio book will not delete

HI  I have Sansa Clip Zip 4GB, have listened to some audiobooks with it.  I am having trouble deleting the books I am done with.  while I try deleting from the clip it will not remove the book/chapter.  When I try using windows while hook up to computer, I get an error message “Storage is write-protected” remove and try again.  As this is happening to each book on the  clip I do not have much room left as I can not delete the files.  They will not move to the recycle bin. Please advise on how to remove the files from the player or how to remove the “Storage is write-protected” while the files are on the clip.

Thank you in advance for your help.


A temporary fix may be to format the player under its Settings–this will erase all the usr content on the player (copy anything you want to save to your computer first). 

But not sure why this ishappening in the first place.  Are the files you are transferring write-protected to begin with, perhaps?