I have a problem regarding this USB 2.0 flashdisk A-Data RB19, 4 GB (rubber sheath): http://www.adata.com.tw/adata_en/product_show.php?ProductNo=AR19ZZZOR After I had been trying to write a file on it (in OS Win XP SP2, build 2600) a strange disk failure occured having caused that I can neither read from it nor write on it ever since. The OS mounts (attaches) the flashdisk on, however, for some reason it just ignores all of my attempts to read from/write on it. Is it possible for the whole FAT filesystem to be damaged or is this a case just with a couple of damaged clusters ? It is not possible to format the flashdisk via the native OS Windows Format utility. I downloaded the special formatting utility designed to be used just with my flashdisk's model from the manufacturer's website but after having it run it returned (after a considerable time) the error message back having announced that no flashdisk was attached (although it was). I just hope it did not go off definitivelly :-/ In advance, thanks to anyone for your help !

 Welcome to HotHardware,I think your best option is to reformat.