Best FREE Windows Malicious Software Removal Tools (Updated)

These are the best free utilities for fighting malicious software (aka Malware). Malware can be defined as any software that installs itself on your computer without your permission, generally these types of programs will try to: monitor your computer activity, destroy data, steal information or steal resources (such as processor, memory, and network bandwidth) for malicious activities.

The programs listed below will help you fight against these types of malicious software by helping you to detect, remove, and prevent your system from getting infected in the first place.

Anti-Virus Scanners (Real-time)
Protects your system in real-time, which can prevent or limit the effects of an virus infection.

• Avast (Home Edition)
  
• AVG (Free Edition)
• AntiVir (Free Edition)
  

Anti-Virus Scanners (Standalone)
These tools can test if a system is infected, or for disinfecting it after it has been contaminated.

• avast! Virus Cleaner
• Trend Micro Sysclean
• Note: Read the README.TXT file for update instructions.
• Clam AntiVirus
• Malicious Software Removal Tool
  

Anti-Virus Scanners (Online)
These tools can test if a system is infected, or for disinfecting it after it has been contaminated.

• ActiveScan (Panda Software)
• OneCare Safety Scanner (Microsoft)
• Kaspersky Online Scanner
  

Malware Scanners
Checks your system for different types of malware (spyware, keyboard loggers, trojans, etc.).

• BitDefender - Free Edition (Trailware)
• Microsoft Defender (included with Windows Vista)
  
• Spybot S&D
• Webroot Spy Sweeper (Trailware)

Online File Scanners
If you receive a file that you think may contain malicious code, you can upload or send it to one of the following sites below to have it scanned.

• Kaspersky File Scanner

Security Tools
These programs can help protect your computer from getting infected or help you detect the existence of malicious software.

• HijackThis (Finds malware by displaying changes to your system)
  
• WinPatrol (Displays the contents of the critical areas in the registry and your hard drive)
• ProcessExplorer (Displays processes running on your system)
• AutoRuns (Lists programs that startup automatically)
  

I have tried to make this list as complete as possible, so if you feel that I am missing a great site or program that should be included in this list please feel free to e-mail me (use the 'Send Comments' link on the side to this page to e-mail me). I will include all the updates in this post as soon as I am made aware of them and verified the site.