Shift keys,logitech K200 keyboard nt working

Hello,

one month back i bought logitech keboard model K200, NOW all of sudden shift keys are not working , it seems like a hardware falut but would like to confirm once gain , is there any solution for the same , i checked the same keyboard connecting to my laptopn and observed the same behavior, could you please suggest the issue

SYSTEM OS-WINDOWS XP


THANKS
GIRI