For a nice GUI tool, there is File Shredder.
With File Shredder you can remove
files from your hard drive without
fear they could be recovered. There
are quite a few software tools today
for retrieval of deleted files under
Windows OS. Those tools, often
referred to as "file recovery"
software, are taking advantage of
shortcoming of WIndows "delete"
command that we all use regularly to
delete files. Actually, the "delete"
operation in Windows only removes bits
of information from files so they
appear deleted in OS. It is easy to
retrieve those files using
aforementioned specialized file
recovery software.
In order to remove, or shred files
permanently from your system you have
to use a program that is capable of
rewriting the files with random series
of binary data multiple times. This
process is often called shredding.
That way, the actual content of the
file has been overwritten and the
possibilities to recover such a
shredded file are mostly theoretical.
For a CLI approach, Sysinternals SDelete is excellent.
The only way to ensure that deleted
files, as well as files that you
encrypt with EFS, are safe from
recovery is to use a secure delete
application. Secure delete
applications overwrite a deleted
file's on-disk data using techiques
that are shown to make disk data
unrecoverable, even using recovery
technology that can read patterns in
magnetic media that reveal weakly
deleted files. SDelete (Secure Delete)
is such an application. You can use
SDelete both to securely delete
existing files, as well as to securely
erase any file data that exists in the
unallocated portions of a disk
(including files that you have already
deleted or encrypted). SDelete
implements the Department of Defense
clearing and sanitizing standard DOD
5220.22-M, to give you confidence that once deleted with SDelete, your file
data is gone forever. Note that
SDelete securely deletes file data,
but not file names located in free
disk space.
Usage: sdelete [-p passes] [-s] [-q]
sdelete [-p passes] [-z|-c] [drive letter]
-c Zero free space (good for virtual disk optimization).
-p passes Specifies number of overwrite passes.
-s Recurse subdirectories.
-q Don't print errors (quiet).
-z Cleanse free space.
Both tools are freeware.
