When an USB flash drive goes wrong in a way that you could not format or access it with your window explorer, you have to recover it with low level format tool.
Common Causes are: 1. fake flash drive 2. flash drive removal without using "safely remove hardware" 3. Unplug flash drive while file writing to it
Common errors are: 1. "unable to access" 2. "track 0 error" 3. "write protection" 4. "Size is 0 byte"
The method is applicable to pen drive or any kind of flash memory - SDHC, microSD, CF and etc.
Step
Download and Install Low Level Format Tool (LLF)
Step
http://hddguru.com/content/en/software/2006.04.12-HDD-Low-Level-Format-Tool/
Step
Insert Your USB Flash Drive and Start LLF Program
Step
You will see your USB flash drive is showed inside the program window. Click on your USB flash drive and then click continue.
Step
Formatting Your Flash Drive
Step
Click on "Low-Level Format" in Tab You data will be erased and irreversible. If you want to recover your data, please check my another article.
Step
It will take roughly 15 min on 4GB or longer on bigger flash drive size.
Step
Verify Your USB Flash Drive
Step
Click on window explorer and check your new formatted flash drive.
