Hard Wipe: Delete Files Permanently on Windows
Windows will not delete files permanently when you delete them from recycle bin. The deleted files are only just marked as not being available, and the deleted file's data disks space is set to be available again for new data. The advantage of this method is that you can recover the data back using data recovery software. The disadvantage, your data is not really erased so that it can be recover back by anyone who uses that computer. This applies when you sell your computer, give it to a friend or someone has stolen your computer.