As human are not free from deficiency syndromes called virus so also our computers are not free from malicious software (malware) called virus, but one thing common about both the human virus and computer virus is that these virus infections are directly or indirectly caused by oneself.
Detect Computer virus spyware malware
What does malicious software (virus) really mean? It is software that is specifically designed to gain access or damage a computer without the knowledge of the owner.

How to Know if Your Computer Has Virus, Spyware, or Malicious Programs


  • The computer is really slow.
  • Nothing responds when you click on an icon and/or your software applications do not work correctly anymore.
  • The system reboots, freezes up, or crashes for no reason.
  • Your antivirus security system and/or firewall are suddenly disabled.
  • You can’t access your disk drive or hard drive.
  • You are suddenly unable to print.
  • You start seeing pop up advertisement windows at unexpected (random) times or unusual programs that start automatically.
  • You have major problems trying to install or download antivirus software or any other software.
  • You seem to have suddenly lost the icons on the desktop and/or all other program files in your folders.
  • New browser homepage, new toolbars and/or unwanted websites accessed without your permission.


Conclusion

As I said earlier computer virus infection are most time directly or indirectly caused by oneself, by installing crack version of a software, downloading software from unreliable website etc.

Note: Some malware (virus) can over power most antivirus software and it will make the computer vulnerable for malicious actions.

The major way to keep your information or document save on your computer is to be mindful of the Software, USB Drive and Website that you associate with your computer.