If you by mistake deleted files from USB flash drive, do not worry, it is possible to get back lost files from USB drive. See this step by step USB data recovery software
How to recover deleted files from USB
The USB data recovery software is easy to use. Just few mouse clicks and you can restore deleted and formatted files from USB drive.
The USB data recovery program is easy to use. Just few mouse clicks and you can recover deleted and formatted files from USB memory stick. You can recover deleted and formatted photos, videos, songs, documents, and other files. The USB data recovery software is able to restore lost files from all USB flash drive, memory stick, pen drive, thumb drive, and other usb storage and external drives.
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Sandisk file recovery freeware - recover deleted formatted photo video files from Sandisk usb flash drive memory cards 