How do you know your computer is virus free?

Answer 1

To keep your computer virus free:

• Have an antivirus program and update it from time to time (some even update automatically)
• Use a firewall.
  
• Only download files from sources you trust.
• Don't open e-mail attachments, unless you know who sent it.
• For more protection you can scan your computer with online scanners provided free by some of the best companies.