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H2testw allows you to test storage devices for various errors. It is particularly useful for detecting fake USB memory sticks/cards, where it attempts to detect the actual capacity versus the reported capacity of the memory stick. Note: H2testw wipes out all the content on the target device during testing! Be sure to backup the content on the device before running H2testw.
H2testw software download: http://www.download3k.com/Install-H2testw.html