No more Viruses....!

 What is a computer virus?

A computer virus is a program that replicates itself.  It spreads by making copies of itself on a computer or by inserting computer code in to program or operating system files. Viruses can damage the computers or may slow down the performance and affects the stability of operating system. There is a huge number of viruses released in to the network. Your computer might get infected with these viruses through various ways.

How do you get a virus in to your computer?

• Through the internet

             •    Opening an infected E-mail attachment
             •    Downloading infected files

• Through the infected removable media (e.g. Floppy drives, USB flash drives, mobile phones etc.)

How do I know if my computer has a virus?

There is no single indicator of virus infection, but of the common effects include
•    Reduced performance of the computer
•    Error messages
•    Pop-up adds displaying
•    Inability to initiate some programs
Sometimes you might not be able to do any work with your computer.
Once your computer is infected with viruses they can be removed by various ways. But some of their effects may persist even after removal. In some instances you might have to reinstall some programs or even operating system. To avoid this, prevention of entering viruses to your computer is what you should do.


How to prevent viruses entering your computer?

1.    Install a good antivirus program. Trial versions of many antivirus programs can be freely downloaded from various websites.
2.    Keep your antivirus program up to date. (run daily update)
3.    Turn on your antivirus program always when you connect to the internet.
4.    Scan incoming E-mails. Since viruses can be attached to E-mails, it is better to not to open any attachment if you are not sure about.
5.    Avoid inserting removable medias which contain viruses.
6.    Turn on antivirus software before inserting removable media.
7.    If you don’t have an antivirus software, insert USB flash drives holding down the “shift” key on your key board. This will prevent auto running of viruses in pen drive.

There is a way to find out whether the USB pen drive contains viruses , without help of an antivirus software. This can be done by using command prompt.
To open command prompt in Microsoft windows you can do the following steps.

a)    Start menu -> All programs -> Accessories -> command prompt
                                Or
b)    Start menu  -> run;
       Then type ‘cmd’ and press ‘enter’.
                               Or
c)    Press windows logo key +R
       Then type ‘cmd’ and press ‘enter’.

Then following window appears.

Next step is to go to the particular drive through command prompt.
To do this type the drive letter followed by : and press ‘enter’. (e.g. F: or G: ) you can find out this drive letter from My computer. Now you have entered the pen drive via command prompt.

To find out whether there are viruses press ‘tab’ button. If you go on pressing ‘tab’ continuously all files in the pen drive are displayed in alphabetical order. All the files including hidden files and viruses are displayed in this manner.

Then you can manually delete viruses. To do this, you have to identify virus files. If you know what files were there previously on your pen drive, this might be easy. Otherwise you should be familiar with file types and viruses to distinguish viruses from other files. There may be files which end with .exe extension. autorun.inf file is also associated with viruses. You can remove these unnecessary files using same window. It is better to remove all these unknown and unnecessary files after confirming what you need.

To delete all files, you can format the drive.
Use the following command.

format X:        (x= drive letter)
then; press enter

To delete any file using command prompt, del command can be used. But viruses can’t be deleted directly using this command.  Since viruses are made as hidden, read only and system files, their attributes should be changed to make them removable.

Use the following steps:
    Type,    attrib -s -r -h file name     and press enter.
(file names can be obtained by pressing tab key.)

This step should be repeated for every file. Then they can be deleted using del command.
   Type,     del file name

Using attrib command you can unhide hidden files on your hard drive or removable devices. 

8.    Most viruses are designed to attack windows operating system. If you use Linux operating system you can avoid harmful effects of these viruses. several linux operating systems can be freely downloaded.