Guide on how to erase information from your hard drives and thumb drives.

Sure, you could erase the contents of the drive, but keep this in mind: the act of erasing a file does not remove it from a storage device.
I recommend using a hammer!

When you erase/delete a file from your computer, it's not really gone until the areas of the disk it used are overwritten by new information. If you use the normal Windows delete function, the "deleted" file is sent to the Recycle Bin until the space it uses is required by other files. If you use Shift-Delete to bypass the Recycle Bin, the space occupied by the file is marked as available for other files. However, the file could be recovered days or even weeks later with third-party data recovery software. As long as the operating system does not reuse the space occupied by a file with another file, the "deleted" file can be recovered.

Link:
http://gizmodo.com/5489933/leave-no-trace-how-to-completely-erase-your-hard-drives-ssds-and-thumb-drives