Pendrive Problem

[dannydy]

my Pen drive on critical problem, last time it was healthy, when i plugged in the pen drive, it displays Removable Disk, when double click to open, it asks me to format, when going to format then it displays cant able to format "The disk is written for protected".
What should i do,any solution?

 

[gbhall]

many pendrives have a tiny switch to place them in a locked safety mode - knocked it on my accident? Please indicate OS.