Eraser http://eraser.heidi.ie/ FileShredder http://www.fileshredder.org/ DiskRedactor http://www.cezeo.com/products/disk-redactor/ Bleachbit http://bleachbit.sourceforge.net/features SlimCleaner http://slimcleaner.com/features.php Paidone : R-Wipe&Clean http://www.r-wipe.com/ Rules.
h2testw from http://www.heise.de/ct/c-t-Systeminfo-473388.html, the page is in German but this freeware can display English. Very efficient and can be stopped/restarted. Used to test HDD and flashkeys.