Eraser [1] is a free, GNU license utility that will securely erase files, folders or even whole disks from any Windows or DOS PC. Eraser overwrites data area with selectable random data patterns and also wipes data in the paging file, Internet cache, temporary files, Internet cookies, unused disk space and a number of other places where data can secretly lurk. It handles FAT16, FAT32 and NTFS partitions as well. Erasing files with high security will always be a difficult and time consuming task and can never offer absolute 100% safety. However Eraser makes the task about as easy as it be, with a security level beyond most conceivable requirements. The author's site is sometimes unavailable but you can find Eraser at numerous download sites including MajorGeeks [2].
Be aware that the current version of Eraser has a bug that is evident if you select the option to erase unused disk space. Stay well clear of that option as you may end up corrupting your drive.
If Eraser is overkill for your needs try Simple File Shredder[3]. It's not as comprehensive a solution to secure deletion as Eraser but it's much easier to use.
Another rather different alternative is Darik's Boot and Nuke [3]. Its an Open Source program that's used to construct a floppy disk or CD that will automatically wipe the all hard drives of any PC booted from the disk. It's great for bulk disk cleaning of PCs and is useful too as an emergency tool for quickly removing sensitive information.
1]
http://www.heidi.ie/eraser/ Free GNU license, all Windows versions, 2.4MB
[2]
http://www.majorgeeks.com/download4221.html
[2]
http://www.scar5.com Freeware, Windows NT and later, 1.24MB
[3]
http://dban.sourceforge.net/ Free Open Source, All Windows versions, 1.99MB
My source for this is:
http://www.techsupportalert.com
I hope this helps?
Richard