HP Pavilion a257c won't read SD cards

My computer just decided to give up on reading every SD cards except my phone microSD(in an adapter). I may have gone in and changed a setting, where I now know I shouldn't have, and made it where the reader will only read the micro. I was trying to make my micro to where I could put pictures on it from my computer, BUT a box would pop up and say that the card was "write protected" and I couldn't add or delete anything. I changed settings that I thought might enable me to add/delete to the micro from the computer. But I am still unable to add/delete. AND everyone of my mom's SD cards (from cameras) won't work. We have installed all camera programs to the computer, and still nothing.
ALL CARDS ARE 1GB.
The computer has 5 other kinds of readers (SmartMedia, CompactFlashI/II, MemoryStick, USB2.0, and 1394) all work except the MMC/SD.
CARDS ARE 1GB and 2GB..
What can I do to make the reader work for all SD cards?