Cannot put more games on MicroSD card

I have recently been introduced to the Legend of Zelda games and was trying to put a Zelda game onto my MicroSD card. It popped up with Cannot copy 1456 - Zelda Phantom Hourglass (U)(iND): The disk is write-protected Remove the write-protection or use another disk
But I don't know how to remove it and the games currently on my MicroSD work fine on my AK2i. My AK2i has been upgraded to bypass v1.4 on DSi(even though I have a DS Lite).

Three possables1. A switch on your microSD card, unlikely!2. No room on your microSD left to use, Mabe3. Its become corrupt, then best to backup any saves and games and start again by formatting and replace firmware , games and saves

the card being full will not cause a write-protect error. there's a switch either on the microsd or on the adaptor.

Thanks I realized I had been messing around with my adapter and hit lock. I'm sorry that was a rookie mistake.

This is an easy thing to do by accident, you don't even have to be fiddling with the adaptor to do it. Sometimes putting the adaptor in the card reader at the wrong angle is all it takes.