Simple and free guide to removing malware

We often get questions on how to remove various malware. We get asked for help when someone's computer is acting funny. They are sure it isn't malware, because they've run regular scans. What people don't always realize, is there are some ways of scanning that are more effective than others. There are also some anti-virus software and some malware scanners that are more effective than others. I've seen some people desperate to remove malware, and are paying lots of money to some websites that are supposed to 'optimize' and 'clean' their computer.

I've cleaned up a lot of infected systems, and there are some real effective and free software out there that can clean up most any infection. Here's a simple guide to scan and remove malware. If you follow this guide step by step, you can clean up most any infected computer.

1. Boot into safe mode with networking. To do this, tap the appropriate function key repeatedly on startup. It's usually F8.

Once in safe mode with networking, download, install, and update Malwarebytes. Do a full system scan.
www.malwarebytes.org/

This is a great program that will detect and remove most any malware. It's very important to do this in safe mode with networking. There are far less services and programs running in safe mode, it's less likely that there will be an active infection running, that will suppress your malware scan. This is why people can run scans all day long, and never find anything. The malware is suppressing the scan before it even starts.

2. Download and run Combofix.
http://www.bleepingcomputer.com/co [...] e-combofix

This is a powerful tool for removing malware. It runs several stages to systematically scan and purge any and all infections. This is a good way to verify that malwarebytes has removed everything.

Combofix doesn't run well on 64bit operating systems. So, if you have a 64bit OS, substitute Spybot Search and Destroy.
http://www.safer-networking.org/index2.html

3. Download and install ccleaner. Use the registry tool to scan and repair all issues. You may need to run this several times to resolve all the issues.
http://www.piriform.com/ccleaner

This will attempt to repair any registry damage, inflicted by the malware. In addition to the registry tool, it has several other useful optimization tools to help keep your PC clean. There is also a nice uninstaller.

Any registry editing can be risky. If it makes you feel better, you can backup your registry before using this registry tool. However, this program is fairly conservative, and very reliable. I've never seen it cause adverse effects.

4. Install a quality anti-virus software.

There are a ton of different options out there. Some use more resources than others. Some catch and stop more potential threats than others. Some have optimization features. Some have annoying pop-ups. The choice here may vary from user to user. However, I'll list what I believe to be the best options, in my order of preference.

Avast free
http://www.avast.com/index

Microsoft Security Essentials
http://www.microsoft.com/security_essentials/

Avira AntiVir Personal - Free Antivirus
http://www.avira.com/en/download/index.php

If your browser is being hijacked try CWShredder Thanks to 4Ryan6 for the suggestion!
http://free.antivirus.com/cwshredder/

If your computer won't boot into safe mode, create a bootable rescue disc, using this guide. You can remove most malware without having to boot into windows. Once done, I would recommend running through this guide, starting with step #1.
http://free.avg.com/us-en/226162
Thanks to Shadow703793 for this suggestion!

Once you have removed any and all infections, a good anti-virus software will help keep you from having to go through this again. However, if you need to remove an infection, just start at #1.