I have 2 card readers in my Velocity micro tower, using XP Pro, and neither is recognized as a drive when i open my computer. There are no question marks or exclamation marks in my system folder. They used to show up as drives F and G, with my WD external showing up as H. (The WD is what I back up to each day and take offsite). Any suggestions as to where they went or how I can get them to show up? Thanks in advance.