Camer is saying memory card is locked, and it isn't

I'm going to give you a diagram to show the correct position of the SD or SDHC memory card lock.
Also the error will show if you haven't formatted the memory card Formatting is generally in your camera set up menu. You didn't say what make or model so i can't assist with this infomration all I can do is suggest you go into the camera set up and scroll through down through the menu to find format or your camera may call it initialize.

Diagram