What does 'Wipe Free Space' do?
What does 'Wipe Free Space' do?
Overwrites deleted files so they cannot be retrieved by recovery software such as Recuva.
Also writes random data in space that never had files.
Also : it doesn't improve performance, it doesn't free up space, and it shouldn't be ran at all unless you want to sell your hard drive.
Why are there so many caveats about WFS? I keep reading (in different posts) recommendations by Aethec never to use it unless selling the computer.
Why not use it? What can it do that is so bad?
Wipe Free Space...wipes the free space. You might already know that when a file is deleted, it's not actually deleted - the content remains, but the operating system changes something (in Windows, there's a bit in the Master File Table to say "this is free" or "this isn't"), so it's like that file didn't exist.
What WFS does is replace all data marked as "free" on your hard drive with zeroes. Since that data was already marked as free, the only benefit of it is to make sure no one will ever recover your data. Windows, as well as all other operating systems, doesn't make a difference between free space holding a previously deleted file, and free space with only zeroes.
Windows, as well as all other operating systems, doesn't make a difference between free space holding a previously deleted file, and free space with only zeroes.
That's because there is no difference. WFS will allocate files large enough to overwrite all free space on a disk, whether that free space contained old deleted file data, or whether it had never been written on before. These files contain binary zeroes. When the disk is full the files are deleted. The end result is that a portion of the disk contains live files with live data, and all other space on the disk contains deleted files which had zeroes as data.
If your life has absolutely no meaning you could, I suppose, do the equivalent of WFS by copying all your dvds to your hard drive until the disk is full, and then delete the lot. Personally that's not for me.