My SD Card Reader Won't Work, Need A Solution

The card reader on my Acer Extensa 4620Z notebook isn't working. I thought at first that it was just a faulty card but it has happened with all four of the cards that i've tried. I've tried switching from locked to unlocked and its the same. The laptop recognizes that there is a card, but when I try and open it it gives me one of the two error messages, "Please insert device into drive F:" or that it is not formatted and when I try and format it, it sais that it cannot be formatted. I have XP on this laptop, and I haven't been able to find a driver to see if that's the problem so I need help with this.