CCleaner is a freeware system optimization, privacy and cleaning tool. It removes unused files from your system - allowing Windows to run faster and freeing up valuable hard disk space. It also cleans traces of your online activities such as your Internet history. Additionally it contains a fully featured registry cleaner and start up programs management option
Can detect and remove malware that even the most well known anti-virus and anti-malware applications fail to detect. Malwarebytes' Anti-Malware monitors every process and stops malicious processes before they even start.
Autoruns (Handle with care. Experts only)
shows you what programs are configured to run during system bootup or login, and shows you the entries in the order Windows processes them. These programs include ones in your startup folder, Run, RunOnce, and other Registry keys. You can configure Autoruns to show other locations, including Explorer shell extensions, toolbars, browser helper objects, Winlogon notifications, auto-start services, and much more. Autoruns goes way beyond the MSConfig utility bundled with Windows OS
Recuva (pronounced "recover")
is a freeware Windows utility to restore files that have been accidentally deleted from your computer. This includes files emptied from the Recycle bin as well as images and other files that have been deleted by user error from digital camera memory cards or MP3 players. It will even bring back files that have been deleted from your iPod, or by bugs, crashes and viruses!
Easeus Partition Manager
No need to format your HDD to make more space or create new partitions
Free partition solution and disk management utility allows you to extend partition, especially for system drive, settle low disk space problem, manage disk space easily on MBR and GUID partition table (GPT) disk.
Download : http://www.easeus-down.com/download/epm.exe