Hard Drive lost while doing Defrag

I am running XP and have 3 internal hard drives,
after defrging the first 2, the third hard drive whilst defraging at 33% stops, (Disk cannot be defragged) appears. trying to open files on E: the PC freezes, am unable to open or tranfer files & photos. After rebooting I try to open and get the message(Drive not Formatted, do you want to format).