How to change memory card password settings

Hello,

I am using 5800 xpressmusic, I could reach my files at first but then I dont know what happened, my computer and also my printer,which has a property of reading memory cards), can not read files on my memory card.. However when I connect my phone with pc suit mode pc can read but nokia ovi suit can not read musics on my card, but sometimes can read images(Synchronization module). By the way when I use a card reader and connect it on my pc, something connected ring is ringing but then removed sound rings, I looked my card is shown in disk management where we can open it from my computer's advanced manage but when I open my computer my card isnt shown at there. I read a topic and there was said that you should disable password of memory card, I couldn't find a setting of it how can I disable it. I didn't set any password for my memory card..