HDD recognition problems after upgrade

Hi- I have Samsung HD300LD with PCClone ExLite one touch system for backing up data. Recently Microsoft asked me to update my Xp SP2 – so I did…… now I cant see the USB device when I press the button to back up. I have browsed some screens and am not that computer savvy but when I go into device manager , the USB and driver can be seen. I dont want to go and buy a new HDD until exploring if I can fix this. Please help!!