Erase not delete
By default Microsoft Windows offers the ability to delete files. However deleting is not the same as erasing because deleted files can be restored and recovered. If you want to delete a file permanetly with no chance of you or anyone else ever being able to recover it, then you need to erase it.
What delete really does
When you delete a file in Windows you move it to the recycling bin, which is just another folder taking up space on your PC. The deleted files are there should you ever want them back again. Maybe you deleted them by mistake and just realised that you really needed that file you just deleted. Well getting the deleted file back is just a matter of going into the recycle bin, selecting the file and restoring it. Voila! It's back to it's original location, as good as new.
If you really did want to delete the file, then you can empty the recycle bin. So now the file is deleted right? Well, not really. All that Windows did was remove the pointers to the file so it won't know where to find it on your hard drive. A file recovery program can still recover it, unless it's been written over by a new file, but that isn't guaranteed and it might still be possible to recover the file.
Erasing a file
When you erase a file you remove it from the hard drive so that it is gone completely. Some erase programs go so far as to employ complex erasure methods so that not even a computer forensic expert can recover the file. It's like it never existed, which is great if you want to erase sensitive files such as those containing private information such as bank account details.
Erase programs work by writing random blocks of data to the location on the hard drive where the file is located, over and over again making it pretty much impossible for anyone to come along and recover even a faint trace of what the file once was, or contained.
If you want to remove files from your Windows PC so that there is no chance that they can ever be recovered again, then install a good erase tool and don't just rely on the built-in delete feature.
Article date: 26th January 2011