CCleaner from Periform

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. But the best part is that it's fast (normally taking less than a second to run) and contains NO Spyware or Adware! :)

Avast! Free Edition

The free version of Avast! is arguably the most comprehensive set of freely available security features on the market. There's a reason these guys have more than 150 million active users (at the time this review was written). The antivirus, antispyware, and heuristics engines form a security core that also includes multiple real-time shields.

Malwarebytes Anti-Malware

Malwarebytes technology takes the next step in the fight against malware. Malwarebytes Anti-Malware PRO detects and removes malware where even the best known anti-virus and anti-malware applications fail.

Malwarebytes Anti-Malware PRO monitors every process and stops malicious processes before they even start. The Proactive Protection Module keeps your system safe and secure with advanced heuristic scanning technology.

Free Office Product Suite

LibreOffice is the power-packed free Open Source personal productivity suite for Windows, Macintosh and GNU/Linux, that gives you six feature-rich applications for all your document production and data processing needs: Writer, Calc, Impress, Draw, Math and Base. LibreOffice has a large and dedicate community of users, contributers and developers that offer free user support and documentation. You, too, can get involved!