Micro SD card Forgot password

I have a micro sd card that was in my cellphone and I put a password a while ago for it... and I forgot it.. I can't seem to format by my cell (it requires the password) and when I try to connect it to the pc ( Via card readers / digital cams/gps/ mobile) my card doesn't appear... PC doesn't recognize it and if I put other micro sd card (w/o password) my pc installs it and reads it. I have a windows7 please any help to recover it or can I just throw it away? ( I don't care about files on it):4-dontkno