H2testw is a simple and free diagnostic tool for speed testing and error detection on USB storage media, memory cards and external and internal hard drives. The application will be useful in case of suspicion of smaller than declared by the manufacturer, capacity and speed of writing and reading data. Test activities are limited to indicating the media, selecting a memory area and starting the analysis.

The test of filling the free space with text files, which are then read, can be done once or select the loop option (in which case the process will stop when the first error is encountered). Importantly, the tool does not delete or overwrite existing data and does not require administrator privileges. When the process is complete, information about encountered errors and actual speeds is displayed.

If there is a suspicion of media damage, the manufacturer recommends that the media be formatted quickly before starting the test. If the device is defective, a significant drop in transfer rate and an extended time to complete the diagnosis should be expected. Also remember not to use port extensions when testing.

Before advertising hardware, it is advisable to check the device in another USB/FireWire port and if external drives are connected, replace the cable.