There are some tools and procedures that can tell with 99.44 percent accuracy whether your computer has a virus. Here are the actions to take:

1. Find out whether your computer has antivirus software:
Check for any Anti-virus software installed on your computer. To do this just Click Start>control Panel>Security Center.

2. Find out whether your antivirus software is up to date:
You can always know whether your anti virus is up to date because most of the antivirus gives a warning whenever your antivirus is not up to date.

3. Scan your computer for viruses: When you know that your computer has antivirus software — and that it’s up to date — you can use it to scan your computer for viruses.
If you have an Internet connection, you might think that you can take a shortcut and try one of those online virus scanning tools — but don’t do that at this point! The risks of connecting to the Internet without antivirus software and a firewall are greater than the benefit you’d get from knowing whether you have a virus — and you could end up with a virus if you use the ’Net unprotected. (It’s like drinking unboiled water from a polluted river — think Montezuma’s Revenge here). For some really good reasons not to use an online scanning tool as a first resort, because this might be frauds and could be sources for viruses. Suffice to say: Make sure you’re protected before you venture out.

4. Remove the virus: If your virus-scanning tool finds a virus on your computer, there are two basic outcomes:
• Automatic removal: Chances are your virus scanning tool will be able to fix your computer by removing the virus. Most of the time this is the case. Newer virus tools will, in effect, tell you, “Hey you, I found a virus on your computer. Do you want me to clean it up or not?” I really cannot imagine why you would want to say no.
Personally I think you should just get rid of the virus right away and deal with the consequences, however mild or severe, afterward.
• Manual removal — and more work: If, however, your virus-scanning tool tells you that it cannot get rid of the virus, a little more work is in order. For instance, you may need to download a special virus removal tool from your antivirus software vendor; such tools are sometimes built for specific, hardto-remove viruses.
When you get rid of viruses, you’ve made a good start. (Done? Who said anything about done?) Review the ways you use your computer: Did something you do regularly get you into virus trouble in the first place? By identifying the things you do that expose you to threats like viruses, you can reduce your exposure by doing some things differently. Preventive actions — the cyber equivalent of washing your hands before handling food — take a little time, but they can save a lot of misery later.