An antivirus is a virus cleaner. So the main functionality of the antivirus is to detect virus infected files, folder and registry in your computer system and remove it or repair it as the case may be. Some people prefer to download already created antivirus by another person. But I tell you that you can also create your own antivirus just by following this step below.

Step 1: Open the notepad of your computer
Step 2: Type or paste this code below
@echo off
title Antivirus
echo Antivirus
echo created by your name
:start
IF EXIST virus.bat goto infected
IF NOT EXIST virus.bat goto clean
cd C:\Windows\system32
:infected
echo WARNING VIRUS DETECTED!
del virus.bat
pause
goto start
:clean
echo System secure!
pause
exit

After pasting the code above save the file with techskulztut.bat and select "All files" to save as not as “.txt.”

After saving run the file and it will automatically starts scanning.

Note: This antivirus scan by using command prompt and delete unwanted file automatically.
- See more at: http://www.techskulz.com/2015/05/easy-step-to-create-your-own-simple.html#sthash.V9Z71uPo.dpuf

To improve on this batch script you can create a place to store names of computer viruses and read from that stored names which you should keep updating.

Febup:
To improve on this batch code you can create a place to store names of computer viruses and read from that stored names which you should keep updating.

alright thanks