I bought my first kingston flash drive with 128mb capacity since 2006 and still working which we use in netcafe. I bought again a kingston (cheap price) 2 gig capacity last november and use it only for 5 months which turn out to be defective. Maybe flash drives that being sold to a certain store with cheap price we're slightly defective which trigger at it mark or point from using a period of time will result defectivity.Defective flash drives discarded by manufacturers are often scavenged and sold cheaply. Such a drive may be labeled as a 1 GB to 64 GB capacity, and your computer may even identify it as that size. But in fact, all but a handful of the bytes on the defective flash drive may be unusable.
Fortunately, there is a free, easy way to determine the true capacity of any flash drive. H2testw is a free, tiny utility that writes test data to a directory on your flash drive, reads it back, and verifies that what was written is what is read back. It was developed to test USB sticks for various kinds of errors. It can also be used for any other storage media like memory cards, internal and external hard drives and even network volumes. It's safe to use H2testw on a flash drive that already has data on it; no existing data will be overwritten or altered. But those untouched parts of the flash drive may contain defective transistors, so it's a good idea to run H2testw on an empty drive, after quick-formatting the drive.networld