Delete On Click - secure delete utility
DeleteOnClick is a free very simple to use file secure delete utility for Microsoft Windows 98SE/ME/ 2000/XP/2003 and Vista.
Cleanup Assistant for windows
Cleanup Assistant is a set of 7 tools that help you keep a clean hard drive.
Disk Cleaner - for Windows Vista and Windows XP
Every day the programs on your computer create temporary and garbage files and leave them behind on your hard disk. These files build up over time, taking up valuable hard disk space and slowing your system down.
Data recovery software
TestDisk is a powerful free data recovery software! It was primarily designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy.
Retrieve accidentally deleted files
Quick and effective way to retrieve accidentally deleted files …
PC Defragmentation Tool
Free Defragmentation tool… Defraggler.
It differs from other defrag tools on the market, by enabling you to quickly and simply defrag the files you want to, without having to process the whole drive. Simply run it, select the file and defragment in seconds. No more struggling with the Windows defragmentation tool.