How to remove a computer virus

Even for an expert, removing a virus from a computer can be a daunting task without the help of tools designed for the job.

Some viruses and other unwanted software (including spyware) are even designed to reinstall themselves after they have been detected and removed.

Fortunately, by updating your computer and using free, trial-period, or low-cost antivirus tools, you can help permanently remove (and prevent) unwanted software.
Steps to help remove a virus:

1.


Visit Microsoft Update and install the latest updates.

2.


If you currently use antivirus software, visit the manufacturer's Web site, update your software, and then perform a thorough scan of your computer. If you don't use antivirus software, subscribe to a service and scan your computer immediately.

3.


Download, install, and run the Malicious Software Removal Tool. Note that this tool does not prevent viruses from infecting your system; it helps to remove existing viruses.
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Why didn't my antivirus software work?

It's crucial to keep your antivirus software current with the latest updates (usually called definition files) that help the tool identify and remove the latest threats.

In addition, not all antivirus tools are the same; if you find that the one you use isn't working to your satisfaction, you should do some research and try an alternative.

Note: What you might think is a virus could actually be spyware. Download and install Windows Defender or other antispyware software to see if that fixes the problem. Windows Defender comes with Windows Vista. If you use Windows XP SP2, you can download Windows Defender for no charge.
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How do I install updates and antivirus software if I can't use my computer?

It might be difficult to download tools or update your computer if your computer has a virus. In this case, use a friend's or other computer to download the tools to a disk, or get support from Microsoft.


Source by: http://www.microsoft.com/protect/computer/viruses/remove.mspx