Spybot Search & Destroy 2.0

Spybot - Search & Destroy detects and removes spyware, a relatively new kind of threat not yet covered by common anti-virus applications. Spyware silently tracks your surfing behaviour to create a marketing profile for you that is transmitted without your knowledge to the compilers and sold to advertising companies.
If you see new toolbars in your Internet Explorer that you haven't intentionally installed, if your browser crashes inexplicably, or if your home page has been "hijacked" (or changed without your knowledge), your computer is most probably infected with spyware.
Even if you don't see the symptoms, your computer may be infected, because more and more spyware is emerging. Spybot-S&D is free, so there's no harm giving it a try to see if something has invaded your computer.
Spybot-S&D can also clean usage tracks, an interesting function if you share your computer with other users and don't want them to see what you have been working on. And for professional users, Spybot-S&D allows you to fix some registry inconsistencies and extended reports.
 

Download Link:

Spybot Search

HijackThis 2.0.4

HijackThis inspects your computers browser and operating system settings to generate a log file of the current state of your computer. Using HijackThis you can selectively remove unwanted settings and files from your computer. Because the settings identified in a HijackThis log file can belong to both legitimate software and unwanted malware, it is important to use extreme caution when choosing to removing anything using HijackThis.
HijackThis also comes with a process manager, HOSTS file editor, and alternate data stream scanner. 

Download Link:

HijackThis 2.0.4

AVG Free Edition 2013.0.3267 (32-bit)

AVG Anti-Virus Free Edition is trusted antivirus and antispyware protection for Windows available to download for free. In addition, the new included LinkScanner® Active Surf-Shield checks web pages for threats at the only time that matters - when you're about to click that link.
AVG Anti-Virus Free has these following features:

• Award-winning antivirus and antispyware
• Real-time safe internet surfing and searching
• Quality proven by 80 million of users
• Easy to download, install and use
• Protection against viruses and spyware
• Compatible with Windows 7, Windows Vista and Windows XP

AVG Anti-Virus Free Edition is only available for single computer use for home and non commercial use.
This is the 32-bit version. 

Download Link:

AVG 2013