disk eraser (2 products)

Active@ Kill Disk - Hard Drive Eraser 2.0 (Freeware)

Active@ KillDisk is a quality security application that destroys data permanently from any

Mutilate File Wiper 2.90 (Shareware, $20.00)

Normal File Deletion is NOT secure. Deleting files merely removes the file system's pointer to the file, ALL THE DATA REMAINS ON YOUR HARD DRIVE OR FLOPPY DISK. The remaining data can be easily recovered with data recovery or forensic software. Your sensitive files may also be vulnerable to advanced recovery techniques, EVEN WHEN OVERWRITTEN, by analyzing latent magnetic traces.