If you by mistake deleted files from SanDisk memory card, or lost files after SanDisk memory card reformat, do not worry, because it is possible to recover deleted files from SanDisk memory card. All you need is a professional data recovery software, here's a good one
How to recover lost files from SanDisk memory card
The SanDisk memory card data recovery program is easy to use. Just few mouse clicks and you can recover deleted and formatted files from SanDisk memory card. You can recover lost files including photos, videos, songs, documents, and other files from SanDisk memory card, sd card, microsd card, sdhc, sdxc, sd mini, cf card. You can restore all lost files such as jpg, png, jpeg, mp4, mkv, avchd, mov, wmv, tif, tiff, gif, mp3, wav, doc, docx, pptx, pdf.
More information
How to download videos from Youtube
External hard disk data recovery solution