Corrupted windows ce oprating system

I HAVE A PALMTOP COMPUTER , BUT MY OPERATING SYSTEM IS NO LONGER WORKING . WHEN I SWITCH IT ON IT DOES NOT BOOT FULLY , IT SHOWS FUNNY MESSAGES AND ENDS AT THAT POINT
hOW CAN I RESTORE THE OPERATING SYSTEM SO I CAN USE MY COMPUTER AGAIN IN A NORMAL WOEKING CONDITION?