On a 200 gig SATA hard drive that is almost full, formatted with NTFS, under WIN XP Pro, SP1, most of the data suddenly disappeared. Properties of the drive shows that it is almost full, yet the actual data appears only to take up about 38 gig. Most of the files were larger video files. Most of the directories and files do not show up during a search. The files that do show up are the ones beginning with numbers and a or b. Changing the attributes does no good. The error when attempting to copy the drive is a "CRC" error. Any suggestions in recovering the data on the drive?