How to unlock/unprotect the memory card of canon digital camera

take out the sd card
look along sides of the card for a slider
slide the slider thing opposite way
put the card into the PC again
delete files
 


Did that it still says locked.
 
It could be that something in the camera is pushing the switch to 'locked' whenever you put it in (mine was doing this.) A small piece of tape over the SD card switch seems to be working for now...