What is a computer virus?

A computer virus is a small software program that spreads from one computer to another computer and that interferes with computer operation. A computer virus may corrupt or delete data on a computer, use an e-mail program to spread the virus to other computers, or even delete everything on the hard disk.

Computer viruses are most easily spread by attachments in e-mail messages or by instant messaging messages. Therefore, you must never open an e-mail attachment unless you know who sent the message or unless you are expecting the e-mail attachment. Computer viruses can be disguised as attachments of funny images, greeting cards, or audio and video files. Computer viruses also spread by using downloads on the Internet. Computer viruses can be hidden in pirated software or in other files or programs that you may download. 

Symptoms of a computer virus

 

If you suspect or confirm that your computer is infected with a computer virus, obtain the current antivirus software. The following are some primary indicators that a computer may be infected:

• The computer runs slower than usual.
• The computer stops responding, or it locks up frequently.
• The computer crashes, and then it restarts every few minutes.
• The computer restarts on its own. Additionally, the computer does not run as usual.
• Applications on the computer do not work correctly.
• Disks or disk drives are inaccessible.
• You cannot print items correctly.
• You see unusual error messages.
• You see distorted menus and dialog boxes.
• There is a double extension on an attachment that you recently opened, such as a .jpg, .vbs, .gif, or .exe. extension.
• An antivirus program is disabled for no reason. Additionally, the antivirus program cannot be restarted.
• An antivirus program cannot be installed on the computer, or the antivirus program will not run.
• New icons appear on the desktop that you did not put there, or the icons are not associated with any recently installed programs.
• Strange sounds or music plays from the speakers unexpectedly.
• A program disappears from the computer even though you did not intentionally remove the program.

Note These are common signs of infection. However, these signs may also be caused by hardware or software problems that have nothing to do with a computer virus. Unless you run the Microsoft Malicious Software Removal Tool, and then you install industry-standard, up-to-date antivirus software on your computer, you cannot be certain whether a computer is infected with a computer virus or not.

What is Spyware?

  Spyware can install on your computer without your knowledge. These programs can change your computer’s configuration or collect advertising data and personal information. Spyware can track internet searching habits and possibly redirect web site activity.

Symptoms of Spyware

When a computer becomes affected by Spyware, the following may result:

• Slow internet connection.
• Changing your web browser’s home page.
• Loss of internet connectivity.
• Failure to open some programs, including security software.
• Unable to visit specific websites, which may include redirecting you to another one.

How to remove a computer virus and spyware.

 

Even for an expert, removing a computer virus or spyware can be a difficult task without the help of computer malicious software removal tools. Some computer viruses and other unwanted softwarereinstall themselves after the viruses and spyware have been detected and removed. Fortunately, by updating the computer and by using malicious software removal tools, you can help permanently remove unwanted software.

 
To remove a computer virus and other malicious software, follow these steps:

Install the latest updates from Microsoft Update:

1. For Windows Vista and Windows 7:
   1. Click the Pearl (Start) button, then type Windows Update in the search box.
   2. In the results area, click Windows Update.
   3. Click Check for Updates.
   4. Follow the instructions to download and install the latest Windows Updates.
2. For Windows XP:
   1. Click Start, then click Run.
   2. Type sysdm.cpl and press the Enter key.
   3. Click the Automatic Updates tab and choose the Automatic (recommended) option.
   4. Click OK.           
    
3. Rogue security software programs will try to make you think that your machine is infected by a virus and usually prompt you to download and/or buy a removal product. The names of these products usually contain words like “Antivirus,” “Shield,” “Security,” Protection,” “Fixer,” so they appear to be legitimate. They will often run immediately when downloaded, or the next time your computer starts up. Rogue security software can prevent applications from opening, including Internet Explorer, and may display legitimate and very important Windows files as infections. Some typical error messages or pop ups you may receive may contain:
   
   Warning!
   Your computer is infected!
   This computer is infected by spyware and adware.